POLYMER BULLETIN
·
2018
·Vol. 76
·期 5
·2215-2231
·
IF 1.589
Yu Lili,Yao Lin,Li Li,Liu Shaojing,Jia Zhengxuan,Wu Di
The cationic photo-responsive polymeric micelles (mPEG-b-p(DEMA-co-MMA-CL)) with light-switchable cross-linker were designed and fabricated by atom transfer radical polymerization and quaternization. These micelles were well dispersed spherical with positive charge. The efficient release of encapsulated contents can be triggered by light irradiation. No significant toxicity was observed of copolymer and its photolysis residues at concentrations up to 250 μg/mL. The antitumor activity of camptothecin (CPT) in micelles demonstrated that light triggered the release of CPT, which dramatically improves the cytotoxicity after UV irradiation.
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Journal of Applied Spectroscopy
·
2018
·Vol. 85
·期 1
·84-89
·
IF 0.611
Zhang J.,Xia T.,Chen Q.,Sun Q.,Deng Y.,Wang C.
The characteristic absorption spectra of paraformaldehyde and metaldehyde in the terahertz frequency region are obtained by terahertz time-domain spectroscopy (THz-TDS). In order to reduce the absorption of terahertz (THz) wave by water vapor in the air and the background noise, the measurement system was filled with dry air and the measurements were conducted at the temperature of 24°C. Meanwhile, the humidity was controlled within 10% RH. The THz frequency domain spectra of samples and their references from 0 to 2.5 THz were analyzed via Fourier transform. The refractive index and absorption coefficients of the two aldehydes were calculated by the model formulas. From 0.1 to 2.5 THz, there appear two weak absorption peaks at 1.20 and 1.66 THz in the absorption spectra of paraformaldehyde. Only one distinct absorption peak emerges at 1.83 THz for metaldehyde. There are significant differences between the terahertz absorption coefficients of paraformaldehyde and metaldehyde, which can be used as "fingerprints" to identify these substances. Furthermore, the relationship between the average absorption coefficients and mass concentrations was investigated and the average absorption coefficient–mass concentration diagrams of paraformaldehyde and metaldehyde were shown. For paraformaldehyde, there is a linear relationship between the average absorption coefficient and the natural logarithm of mass concentration. For metaldehyde, there exists a simpler linear relationship between the average absorption coefficient and the mass concentration. Because of the characteristics of THz absorption of paraformaldehyde and metaldehyde, the THz-TDS can be applied to the qualitative and quantitative detection of the two aldehydes to reduce the unpredictable hazards due to these substances.
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CHROMATOGRAPHIA
·
2018
·Vol. 81
·期 5
·749-758
·
IF 1.401
Yin Dan,Chen Yanlong,Zhang Yanhao,Yang Zhicong,Mao Hongyan,Xia Shaige,Zhang Wenfen,Zhao Wuduo,Zhang Shusheng
Abstract A rapid and effective solid-phase extraction high-performance liquid chromatography fluorescence detection (SPE-HPLC–FLD) method, using a novel porous aromatic framework (PAF-6) as solid-phase extraction sorbent, was established to enrich and determine bisphenol (BPA) in milk and its packing samples. Parameters influencing the extraction efficiency, such as volume of the sample solutions, pH of the sample, and the eluent volume, were examined. The limits of detection and quantitation were 0.1 and 0.33 ng mL −1 , respectively. The recovery of the method was desirable at 81–91% and the relative standard deviation was less than 2.35%. Besides, the PAF-6-based cartridges exhibited superior reusability for milk sample analysis. In addition, theoretical computations were performed to further understand the molecular interaction mechanism between the PAF-6 and the BPA. The results showed that PAF-6 had an excellent adsorption capability for BPA based on hydrogen bonding and the inclusion interactions of host–guest. The proposed method is sensitive, simple, and cost-saving, and provides a detection platform for the monitoring of BPA residues in real milk samples. Graphical Abstract
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JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2018
·Vol. 316
·期 2
·685-690
·
IF 1.181
Song Hu,Wang Yunhan,Wang Jing,Wang Guanquan,He Jiaheng,Wei Hongyuan,Luo Shunzhong
For the superiority of graphene quantum dots (GQDs) in bioimaging and drug delivery carrier, GQDs bring new opportunities for theranostics of diseases. In this study, GQDs were successfully prepared and labeled with 131 I. The in vitro properties, biodistribution and SPECT imaging of 131 I-GQDs were investigated. The uptake of 131 I-GQDs at tumor sites can be clearly observed via SPECT imaging and T/B and T/M ratios increase with increasing time, which can contribute to enhanced permeability and retention (EPR) effect.
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Nanoscale Research Letters
·
2015
·Vol. 10
·期 1
·1-6
·
IF 2.779
Guo Jing,Pei Yingli,Zhou Zhengji,Zhou Wenhui,Kou Dongxing,Wu Sixin
Solution-processed approach for the deposition of Cu 2 ZnSn (S,Se) 4 (CZTSSe) absorbing layer offers a route for fabricating thin film solar cell that is appealing because of simplified and low-cost manufacturing, large-area coverage, and better compatibility with flexible substrates. In this work, we present a simple solution-based approach for simultaneously dissolving the low-cost elemental Cu, Zn, Sn, S, and Se powder, forming a homogeneous CZTSSe precursor solution in a short time. Dense and compact kesterite CZTSSe thin film with high crystallinity and uniform composition was obtained by selenizing the low-temperature annealed spin-coated precursor film. Standard CZTSSe thin film solar cell based on the selenized CZTSSe thin film was fabricated and an efficiency of 6.4 % was achieved.
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PubMed
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KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2015
·Vol. 33
·期 1
·312-318
·
IF 1.166
Wang Ye,Li Guobing,Chen Song,Si Rongshuang,Fan Jiangyang
Monodisperse micron-size poly(styrene-co-divinylbenzene) (PST-DVB) microspheres were successfully prepared by vibration dispersion. A vibrator was used to generate a controlled vibration to jet from a single nozzle of 200 µm to produce uniform droplets. The effects of variations in selected process parameters upon the droplets formation and the diameter of the microspheres were investigated. It was demonstrated that changes in the velocity of oil phase, drive frequency and destabilization amplitude have significant effects on the formation of uniform droplets and the average diameter of the microspheres. Rational polynomial regression equations of the above parameters were established. Based on these equations, we could calculate the operation conditions to produce uniform droplets with the desirable diameter.
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MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 13
·2251-2258
·
IF 3.741
Wang Minghua,Zhang Shuai,Ye Zihan,Peng Donglai,He Linghao,Yan Fufeng,Yang Yanqin,Zhang Hongzhong,Zhang Zhihong
Multilayered reduced graphene oxide (rGO) was functionalized with amino groups by treatment with nitrogen plasma. Raman spectroscopy showed plasma treatment not to substantially alter the chemical structure of rGO and that a wide range of functional nitrogen groups is evenly incorporated into the carbon lattice. The amino-modified rGO was used to design an electrochemical biosensor in which a DNAzyme, substrate DNA and Pb(II) and Hg(II) binding DNA were immobilized on the amino-rGO placed on a gold electrode. The high concentration of amino groups and the rough surface of the rGO favor DNA immobilization. Heavy metal ions are bound to the surface via specific interaction between DNA and the two ions which are detected by electrochemical impedance spectroscopy at a potential of 0.2 V (vs. Ag/AgCl). The detection limits for Pb(II) and Hg(II) are as low as 7.8 and 5.4 pM, respectively, and the analytical ranges extend from 0.01 to 100 nM. The sensor is highly specific and stable and therefore represents a highly promising tool for use in environmental monitoring.
A nanofilm of reduced graphene oxide was first modified with amino groups by treatment with nitrogen plasma. A special DNA was then anchored to the surface to obtain a biosensor for simultaneous detection of Pb(II) and Hg(II). The sensor has detection limits as low as 7.8 and 5.4 pM and is highly selective.
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Food Analytical Methods
·
2015
·Vol. 9
·期 1
·88-94
·
IF 1.956
Jiao Zhe,Jiang Zhibin,Zhang Ni
In this study, copper(II) isonicotinate was first used as an online cleanup adsorbent in selective pressurized liquid extraction (SPLE) for determination of trace residues of polychlorinated biphenyls (PCBs) in fatty food samples. The adsorbent-to-sample ratio, extraction temperature, extraction time, recycle times, etc. were optimized. The PCBs in food samples of pork, chicken meat, and clam meat were detected by gas chromatography–mass spectrometry (GC-MS). The detection limit (S/N = 3) ranged from 0.2 ng/g wet weight (PCB 18) to 2.5 ng/g wet weight (PCB 66). Relative standard deviations (%RSDs) were lower than 12.5 %. The mean recovery was in the range of 82.4–105.1 %. Certified reference materials were analyzed with acceptable results. It was exhibited that the copper(II) isonicotinate showed higher purification capacity than other cleanup adsorbents for extraction of PCBs in fatty food. The proposed method which involved extraction-cleanup in one step can be a promising sample preparation method for food analysis.
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Science China-Chemistry
·
2014
·Vol. 58
·期 3
·532-538
·
IF 1.516
Chai XiaoHui,Liu ZhiHong,Huang YingPing
Three different nanorod-like gallium oxides with mono/poly-crystalline nature (α, β, and α/β-Ga 2 O 3 ) were prepared by regulating the amount of polyethylene glycol (PEG) 6000 in the range of 0.2–0.8 g proportionally via a hydrothermal method combined with further calcination. The bandgap of the products, given by UV-Vis diffuse reflectance spectra (UV-Vis DRS), was in the order of α-Ga 2 O 3 > α/β-Ga 2 O 3 > β-Ga 2 O 3 . To further investigate the photocatalysis performance of the catalysts, the decomposition of rhodamine B (RhB) by Ga 2 O 3 under UV light illumination ( λ < 387 nm) was presented and complete degradation could be achieved within 30 min, a result that showed the highest efficiency. The photocatalytic oxidation mechanism is further discussed and prominently related to the active species: hydroxyl radical (·OH) and superoxide radical (O 2
· − ), which were confirmed by electron paramagnetic resonance (EPR).
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JOURNAL OF NANOPARTICLE RESEARCH
·
2013
·Vol. 15
·期 4
·1-9
·
IF 2.175
Jia Li-Ping,Yan Bing,Zhang Qiang
A high temperature solution system with BaCO 3 /RECl 3 ·xH 2 O in oleic acid/1-octadecene has been developed to prepare barium rare earth fluoride nanocrystals: tetragonal phase of BaREF 5 (RE = Pr, Nd, Eu, Tb, Dy, Tm, Lu, Y), pure cubic phase Ba 2 REF 7 (RE = La, Sm, Ho, Er, Yb), and BaREF 5 (RE = Ce, Gd) colloidal nanocrystals. In addition, it is proved that the functionalization of these nanocrystals by means of doping with Eu, Tb, and Yb, Er/Tm ion pair can obtain red, green, and visible-to-the-naked-eye green/blue upconversion emissions.
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CHEMICAL PAPERS
·
2013
·Vol. 67
·期 5
·517-525
·
IF 0.879
Wu Xing,Yi Jian-Min,Liu Yue-Jin,Liu Yong-Bing,Zhang Pan-Liang
The rapid expansion of a supercritical solution (RESS) process represents an attractive prospect for producing sub-micron and nano-particles of medical compounds with low solubility. The solubility of phenacetin in supercritical carbon dioxide was measured by the analytical-isothermal method at pressures ranging from 9.0 MPa to 30.0 MPa and temperatures ranging from 308.0 K to 328.0 K. The results show that the mole fraction solubility of phenacetin in supercritical carbon dioxide is up to 10 −5 . Four density-based semi-empirical models were introduced to correlate the experimental data. Agreement between the model predictions and experimental data is greater with the Adachi-Lu-modified Chrastil model than with the Chrastil model, Méndez-Santiago-Teja model, and the Bartle model and the average absolute relative deviation (AARD) observed is 0.0483. The preparation of fine phenacetin particles by the RESS process under different conditions of extraction temperatures (308.0–328.0 K), extraction pressures (9.0–30.0 MPa), nozzle temperatures (373.0–393.0 K), nozzle diameters (0.1–0.8 mm), and collection distance (20.0–40.0 mm) was investigated. The size and morphology of the resultant particles were analysed by SEM. A remarkable modification in size and morphology can be obtained by condition-optimisation.
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Chemistry Central Journal
·
2012
·Vol. 6
·期 1
·1-10
·
IF 3.281
Li Xican,Lin Jing,Gao Yaoxiang,Han Weijuan,Chen Dongfeng
Background As a typical Chinese herbal medicine, rhizoma Cimicifugae (RC, 升麻 in Chinese) possesses various pharmacological effects involved in antioxidant activity. However, its antioxidant activity has not been reported so far. The aim of the present study was to systematically evaluate the antioxidant ability of RC in vitro, then discuss the mechanism. Methods Firstly, five RC extracts (i.e. petroleum ether extract PERC, ethyl acetate extract EARC, absolute ethanol extract AERC, 95% ethanol extract 95ERC, and water extract WRC) were prepared and determined by various antioxidant methods, including anti-lipidperoxidation, protection against DNA damage, ·OH scavenging, ·O 2 - scavenging, DPPH· (1,1-diphenyl-2-picryl-hydrazl radical) scavenging, ABTS + · (2,2’-azino-bis (3-ethylbenzo- thiazoline-6-sulfonic acid radical ion) scavenging, Cu 2+ -chelating, and Fe 3+ reducing assays. Subsequently, we measured the chemical contents of five RC extracts, including total phenolics, total saponins, total sugars, caffeic acid, ferulic acid and isoferulic acid. Finally, we quantitatively analyzed the correlations between antioxidant levels (1/IC 50 values) and chemical contents. Results In the study, the antioxidant levels and chemical contents (including total phenolics, total saponins, total sugars, caffeic acid, ferulic acid and isoferulic acid) of five RC extracts were determined by various methods. In all antioxidant assays, five RC extracts increased the antioxidant levels in a dose-dependent manner. However, their antioxidant levels (IC 50 values) and chemical contents significantly differed from each other. Quantitative analysis of the correlation showed that total phenolic was of significant positive correlations (average R value was 0.56) with antioxidant levels; In contrast, total sugars and total saponins had no positive correlation with antioxidant (the average R values were −0.20 and −0.26, for total sugars and total saponins, respectively); Among total phenolics, three phenolic acids (caffeic acid, ferulic acid and isoferulic acid) also displayed positive correlations (the average R values were 0.51, 0.50, and 0.51, for caffeic acid, ferulic acid and isoferulic acid, respectively). Conclusions As an effective antioxidant, Rhizoma Cimicifugae can protect DNA and lipids against oxidative damage. Its antioxidant ability can be responsible for its various pharmacological effects and may be mainly attributed to the existence of total phenolics, among which caffeic acid, ferulic acid and isoferulic acid are regarded as main bioactive components. Rhizoma Cimicifugae exerts its antioxidant effect through metal-chelating, and radical-scavenging which is via donating hydrogen atom (H·) and donating electron (e).
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