JOURNAL OF ELECTRONIC MATERIALS
·
2018
·Vol. 47
·期 12
·7514-7519
·
IF 1.566
Zhu Z.,Zhang Y. W.,Song H. Z.,Li X. J.
Cu 1.98− x Na x Se nanopowders were synthesized using a hydrothermal method and hot-pressed into bulk pellets to assess the effects of Na doping on the thermoelectric properties of Cu 1.98 Se. The original layered microstructure was maintained at low doping levels, although nanopores, together with point defects, appeared to decrease the thermal conductivity. The thermoelectric properties of the material were improved by Na doping, resulting in a maximum ZT value of 1.32 for Cu 1.94 Na 0.04 Se at 973 K. The experimental data indicate that an optimal level of Na doping effectively improves the thermoelectric performance of non-stoichiometric Cu 1.98 Se.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 3
·2552-2565
·
IF 2.993
Yang Qingsong,Li Li,Zhao Fang,Han Haoya,Wang Weihua,Tian Yuchuan,Wang Yunwei,Ye Zhishuang,Guo Xuhong
The stimulus-responsive drug delivery system has attracted increasing attention due to its ability to enhance therapeutic efficacy and reduce side effects. Herein, a pH and glutathione (GSH) dually responsive drug carrier, hollow silica–-polyelectrolyte composite nanoparticle, was successfully prepared by using a template of spherical polyelectrolyte brush (SPB) which consists of a polystyrene (PS) core and a densely grafted linear poly(acrylic acid) (PAA) shell. The existence of PAA chains and introduction of disulfide bonds in silica framework endow the composite nanoparticles with pH and GSH dually responsive properties which were confirmed by dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). With doxorubicin hydrochloride (DOX) as the model drug, the loading content and encapsulation efficiency could reach up to 43% and 96%, respectively. The drug release behavior was investigated under various environments, showing that the drug release rate increased with the decrease in pH value and the increase in GSH concentration. The prepared hollow SiO 2 –PAA composite nanoparticles possess a great potential as carriers for controlled drug delivery.
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高影响因子
DIGESTIVE DISEASES AND SCIENCES
·
2018
·Vol. 63
·期 12
·3329-3338
·
IF 2.819
Lin Meng-juan,Yu Bao-ping
Background Irritable bowel syndrome (IBS) is a common disease with intestinal dysmotility, whose mechanism remains elusive. TMEM16A is a calcium-activated chloride channel (CaCC) involved in intestinal slow-wave generation. Aims To investigate whether TMEM16A is involved in colonic dysmotility in IBS. Methods A rat model of IBS was established by chronic water avoidance stress (WAS). Colonic pathological alterations were evaluated histologically, and intestinal motility was assessed by intestinal transit time (ITT) and fecal water content (FWC). Visceral sensitivity was determined by visceromotor response (VMR) to colorectal distension (CRD). TMEM16A expression was evaluated by RT-PCR, Western blot, and immunofluorescence. Colonic muscle strip contractility was measured by isometric transducers, and the effect of niflumic acid (NFA), a CaCC antagonist, on colonic motility was examined. Results After 10 days of WAS exposure, ITT was decreased and FWC was elevated. Furthermore, VMR magnitude of WAS rats in response to CRD was significantly enhanced. Protein and mRNA levels of TMEM16A in colon were considerably increased after WAS. The percentage of TMEM16A-positive neurons in myenteric plexus (MP) of WAS rats was significantly higher than controls. Pharmacological blockade of TMEM16A activity by NFA considerably enhanced ITT, with concentration-dependent declines in FWC and VMR magnitude in NFA-treated rats. Further, spontaneous contraction of colonic strips of NFA-treated rats was significantly ameliorated in a concentration-dependent manner in vitro. Conclusions Upregulation of TMEM16A in MP neurons may play an important role in chronic stress-induced colonic hypermotility, making CaCC-blocking drugs a putatively effective treatment method for colonic hypermotility in IBS.
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PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 23
·15927-15938
·
IF 2.993
Xun Suhang,Hou Caozheng,Li Hongping,He Minqiang,Ma Ruliang,Zhang Ming,Zhu Wenshuai,Li Huaming
The catalyst of WO 3 highly dispersed on mesoporous ZrO 2 was prepared by hydrothermal treatment and calcination. Ionic liquid templates with different cations and various calcination temperatures were taken into account to investigate factors that affect the structure of the catalysts. Wide-angle XRD, Raman, low-angle XRD, N 2 adsorption–desorption, SEM, EDS-mapping and TEM analyses were employed to characterize the composition, morphology and the dispersion of WO 3 . It was found that [C 16 H 33 N(CH 3 ) 3 ] 4 SiW 12 O 40 and 700 °C were the optimal ionic liquid template and calcination temperature; the obtained catalyst, expressed as 700-C 16 -WO 3 /ZrO 2 , exhibited the best catalytic activity in oxidation desulfurization. Dibenzothiophene (DBT) in the model oil could be oxidized to DBT sulfone (DBTO 2 ) completely, certified by GC-MS analysis, under optimum conditions. The oxidative desulfurization efficiencies of different substrates catalyze by 700-C 16 -WO 3 /ZrO 2 , and the cycle performance on the oxidation of DBT were studied.
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高影响因子
Journal of the Iranian Chemical Society
·
2018
·Vol. 15
·期 7
·1561-1568
·
IF 1.593
Liu Chunbo,Liu Zhihua,Wang Meng,Yang Yaling
A novel and simple two-step micro-extraction technique combining surfactant-assisted dispersive liquid–liquid micro-extraction and magnetic solid-phase extraction prior to high-performance liquid chromatography was established for analysis of polyphenols including chlorogenic acid, caffeic acid, and scopoletin in tobacco samples. In the developed system, Fe 3 O 4 nanoparticles were synthesized by a one-step chemical co-precipitation method and used to remove hydrophobic substances in tobacco samples by physical adsorption. Low-density solvent (1-heptanol) and cationic surfactant cethyltrimethyl ammonium bromide were employed as extraction solvent and disperser agent, respectively. Under the optimized experimental conditions, a good linearity of the method was obtained over the concentration range from 0.1 to 1000 ng mL −1 for target analytes. The limits of detection ( S / N = 3) were 0.05 ng mL −1 for CGA, 0.10 ng mL −1 for CFA, and 0.12 ng mL −1 for SP, respectively. Finally, the applicability of the developed method was evaluated by extraction and determination of these three phenolic compounds in tobacco samples and satisfactory average recoveries of spiked samples were between 96.6 and 102.7%.
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高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
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2018
·Vol. 20
·期 4
·1-9
·
IF 2.127
Lü Ting,Qi Dongming,Zhang Dong,Lü Yulan,Zhao Hongting
Oil spills and oily wastewater discharges from ships and industrial activities have serious impacts on the environment and human health. In this study, a class of easy-to-synthesize polyethylenimine (PEI)-coated Fe 3 O 4 magnetic nanoparticles (MNPs) was successfully synthesized via a one-step coprecipitation method. The synthesized PEI-coated Fe 3 O 4 MNPs were characterized by using multiple technologies and applied in emulsified oil-water separation for the first time. It was found that the PEI effectively tuned the surface charge and wettability of MNPs. As a result, the PEI-coated MNPs could successfully assemble at the oil-water interface and promote the coalescence of oil droplets, thereby facilitating the subsequent magnetic separation. Results showed that the oil-water separation performance was superior and enhanced with the increase of ionic strength. Recycling experiment indicated that the PEI-coated MNPs could be reused up to six times without showing a significant decrease in separation efficiency. All of these results suggested that the PEI-coated MNP could potentially be used as a class of promising nanomaterials for emulsified oil-water separation.
Schematic illustration of the emulsified oil-water separation process by using PEI-coated Fe 3 O 4 MNPs.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 10
·8630-8635
·
IF 2.324
Zhang Shaobo,Shi Liwei,Tang Tianliang,Li Shuaiqi,Xia Wangsuo
New microwave dielectric ceramics Mg 2 CeNbO 6.5 were synthesized by solid-state method. The phase, crystal structure, micro-structures and microwave dielectric properties of Mg 2 CeNbO 6.5 ceramics had been investigated in the sintering temperature range of 1225–1325 °C. Two phases were detected by the X-ray diffraction patterns, including the main crystalline phase of CeO 2 and the second phase of Mg 4 Nb 2 O 9 . Well-developed microstructures of the well-dense samples were obtained for samples sintered at 1225–1325 °C. As sintering temperature increased, the τ f values were stable, however, the significant change in the ɛ r values and Q × f values were observed. At 1275 °C, the obtained Mg 2 CeNbO 6.5 ceramics had promising excellent microwave dielectric properties: ε r = 15.38, Q × f = 17,300 GHz and τ f = − 49.71 ppm/°C.
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高影响因子
MICROCHIMICA ACTA
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2018
·Vol. 185
·期 4
·1-9
·
IF 5.705
Xue Qin,Cao Xuanyu,Zhang Cuiling,Xian Yuezhong
The authors describe an environmentally friendly and fast (~14 min) method for the synthesis of homogeneously distributed fluorescent polydopamine nanodots (PDA-NDs) using KMnO 4 as the oxidant. Alkaline phosphatase (ALP) catalyzes the hydrolysis of ascorbic acid 2-phosphate to release free ascorbic acid which undergoes an in-situ redox reaction with KMnO 4 . Depending on the activity of ALP, more or less KMnO 4 is consumed, and this affects the formation of the PDA-NDs. Based on this finding, a sensitive method was worked out to quantify the activity of ALP via real-time formation of fluorescent PDA-NDs. The fluorometric signal (best measured at excitation/emission peaks of 390/500 nm) is linear in the 1 to 50 mU·mL −1 ALP activity range, and the limit of the detection is as low as 0.94 mU·mL −1 (based on 3 σ/m). The method was successfully applied to the determination of ALP activity in spiked human serum and in MCF-7 cell lysates. It was also applied in a method to screen for inhibitors of ALP.
Schematic of a fluorometric method for the determination of alkaline phosphatase (ALP) activity. The method is based on the in-situ regulation of the formation of fluorescent polydopamine nanodots (PDA-NDs) through the competition between the KMnO 4 -induced polymerization of dopamine and ALP-directed ascorbic acid 2-phosphate (Asc-2P) hydrolysis. AA: Ascorbic acid.
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高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 8
·1-7
·
IF 2.184
Huang Yu,Zhan Zhan,Zhang Xiongzhi,Li Houbin,Huang Chi
The composites of anionic spherical polyelectrolyte brushes/conducing polymer (ASPB/CP) have been successfully prepared by chemical oxidative polymerization of aniline and pyrrole monomers in an acidic medium containing anionic spherical polyelectrolyte brushes. These composites were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectrometry, zeta potentials, X-ray photoelectron spectroscopy, and four probe methods. It was found that the poly(aniline- co -pyrrole) was uniformly coated on the surface of ASPB. Besides, the ASPB/CP composites had higher doping level than the pure copolymer after doping with ASPB. Moreover, these composites also showed better solubility and storage stability than pure copolymer. The electrical conductivity of the ASPB/CP composites at room temperature was 7.2 S/cm, while it was 2.4 S/cm for the pure copolymer under the same circumstances.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 50
·期 20
·6567-6577
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IF 2.371
Hu Caibiao,Zhao Guodong,Xia Qiang,Sun Rui
The present study investigated a self-double-emulsifying drug delivery system (SDEDDS) loaded with epigallocatechin-3-gallate (EGCG) and α-lipoic acid to improve EGCG photostability and possess a sustained release behavior. The long chain solid lipids (cetostearyl alcohol) and macadamia oil were utilized as a carrier to co-deliver the two bioactive ingredients. The prepared EA-SDEDDS for topical application was formulated using modified two-step method and characterized by confocal microscopy, in vitro release, and antioxidant effects. EA-SDEDDS was found to be stable under simulated sunlight for 1 month (at room temperature). In vitro cell culture studies, EA-SDEDDS provided protection for 3t3 fibroblasts that underwent H 2 O 2 oxidative stress due to sustained release property. Cellular antioxidant activity assay indicated that EA-SDEDDS showed anti-oxidative capacity with the same efficacy compared to EGCG-α-lipoic acid solution.
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高影响因子
WOOD SCIENCE AND TECHNOLOGY
·
2015
·Vol. 49
·期 4
·755-767
·
IF 1.92
Hui Bin,Li Guoliang,Han Guanghui,Li Yingying,Wang Lijuan,Li Jian
Using chitosan (CS)-modified wood as a scaffold, a magnetic surface was constructed via a simple in situ synthesis method in this paper. The effects of iron ions concentrations on crystalline structure and magnetic properties of the composite were investigated. The composites were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometer (VSM). SEM analysis revealed that the iron oxide particles uniformly deposited on the wood surface. The mineralogy of iron oxide was identified by XRD and XPS analysis as the spinel phase magnetite. In addition, the CS acted as a bridge linking the magnetite coating and wood substrates, which is a key factor for the formation of their strong bonding forces. VSM measurement indicated that the as-synthesized composites were magnetically soft at room temperature, and the saturation magnetizations M
s increased from 14.07 to 57.46 memu, the remanence magnetization M
r increased from 0.57 to 2.77 memu, and the coercivity H
c decreased from 17.02 to 14.29 Oe with an increase in iron ions concentration from 0.4 to 2.0 mol/L. The magnetic property of the composites was easily tailored by adjusting the iron ion concentration, thus providing novel applications of the natural resources wood.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 50
·期 6
·2429-2442
·
IF 2.305
Zhang Han,Xue Yanan,Huang Juan,Xia Xiaoyang,Song Meifang,Wen Kaikai,Zhang Xiaoxiao,Luo Xiaogang,Cai Ning,Long Sihui,Yu Faquan
A charge reversible, magnetic-targeted, and pH-responsive nano therapy system assembled from citraconic-modified dextran (Dex–COOH), glycine-stabilized superparamagnetic iron oxide nanoparticles (SPION–NH 2 ), and doxorubicin (DOX) through electrostatic interaction was designed for delivering therapeutics to tumor cells. Dex–COOH was first synthesized to build the pH-sensitive citraconic amide bond and further render charge reversal upon the cleavage of the linkage. The SPION–NH 2 anchored in the nanocarrier endows the carrier with magnetic migration. The vibrating sample magnetometer analysis exhibits the superparamagnetic behavior, and the magnetic saturation value is estimated to be 39.6 emu (g Fe) −1 . The change of size and the reversal of zeta potential from negative to positive in acidic environment confirmed these expected responsibilities. The DOX-loaded nanocarriers contain DOX up to 13.0 wt%. An in vitro release profile demonstrated an efficient DOX release of 80 % at pH 5.0 while of 27 % at pH 6.8 and 13 % at pH 7.4, suggesting a pH-induced release mechanism. Microscopic images of Prussian blue staining, quantification of cellular iron and protein concentration displayed apparent iron uptake by HeLa cells. Confocal laser scanning microscopy observations revealed that the nanocarriers could efficiently deliver and release DOX into the nuclei of HeLa cells. MTT assays testified that DOX-loaded nanocarrier exhibited high anti-tumor activity with IC 50 of 0.7 μg mL −1 , while plain nanocarriers were practically non-toxic. This drug delivery system has shown the ability to improve the chemotherapeutic efficacy and to reduce the side effects, indicating great potential for delivery of drugs to the targeted sites in patients.
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