JOURNAL OF POROUS MATERIALS
·
2015
·Vol. 22
·期 5
·1357-1362
·
IF 1.108
Yin Liuyan,Zhou Xingui,Yu Jinshan,Wang Honglei
A planetary ball-milling foaming route was employed by the protein foaming method for preparing silicon nitride (Si 3 N 4 ) foams. In comparison with the commonly used tumbling foaming route of protein foaming method, pores of the Si 3 N 4 foams fabricated by this new foaming route are more uniform in size distribution and the pores pack more compact. Furthermore, effects of the rotating speed on the structure and the property of the Si 3 N 4 foams fabricated by this new foaming route were investigated. It was indicated that the average pore size decreased with the rotating speed, whereas the count of windows on the walls increased with the rotating speed. Moreover, the windows were found to have a negative influence on the phase transformation of Si 3 N 4 from α phase to β phase.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 50
·期 18
·6113-6123
·
IF 2.371
Liu Xiaoyan,Zhou Yifeng,Nie Wangyan,Song Linyong,Chen Pengpeng
Novel environmental friendly hydroxypropyl cellulose (HPC) hydrogels were fabricated upon compositing with graphene oxide (GO) in this work. In order to promote a more homogeneous dispersion of GO sheets in HPC, GO was firstly modified with HPC chains through esterification. The morphology and chemical structure of the functionalized HPC-GO were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometer, X-ray diffraction, and thermo-gravimetric analysis. Then scanning electronic microscope was employed to compare the morphologies of the HPC and HPC-GO/HPC hydrogels. The obtained HPC-GO/HPC hydrogels exhibited excellent adsorption performance toward methylene blue. Simulation of the practical use by preparing simple adsorption columns made from in situ formation of HPC-based hydrogels had given a visible observation of the significant adsorption effect brought by the incorporation of HPC-GO sheets. Adsorption kinetics were then imitated by Lagergren pseudo-first-order and pseudo-second-order models. Adsorption isotherms were imitated by Langmuir isotherm and Freundlich isotherm.
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高影响因子
CELL BIOCHEMISTRY AND BIOPHYSICS
·
2014
·Vol. 71
·期 1
·367-373
·
IF 2.38
Gan Maozhou,Yin Xiaodong
This research designed to explore the antitumor activity of puerarin against human mantle cell lymphoma (MCL). Cell proliferation and apoptosis were assessed by MTS and flow cytometry. Caspase-3, -8, and -9 activities were assessed with the colorimetric caspase protease assay. Apoptotic proteins like PARP, cyclin D1, Bcl-2 family, XIAP, and cIAP I were researched by western blot. The PI3K inhibitor LY294002 was used to investigate the possible mechanism relating the PI3K/Akt signaling pathway. Puerarin in vitro inhibited proliferation and induced apoptosis of Z138 cells. Expressions of PI3K and p-Akt were downregulated by puerarin. Puerarin negatively regulated NF-κB activity by inhibiting NF-κB phosphorylation with nuclear translocation inhibition. This kind of effects was correlated with the suppression of expression of cyclin D1, BAX, Bcl-2, XIAP etc. This function was modulated by the PI3K inhibitor. Our results demonstrated that puerarin can induce growth arrest and apoptosis in MCL cells and that the mechanism may involve the NF-κB signaling pathway. Puerarin may have therapeutic applications in the treatment of MCL.
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PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2014
·Vol. 21
·期 9
·1-8
·
IF 1.897
Liu Xin,Cheng Jue,Zhang Junying
A facile method is described for preparing thermal plastic polyurethane-polystyrene (PUPS) block copolymer. 2-Hydroxy-2-methyl-1-phenyl-1-propanone (HMPP)-capped polyurethane was synthesized and used as macrophotointiator to prepare PUPS by ultraviolet (UV) irradiation polymerization of styrene. The polymerization process of PUPS block copolymer was monitored by real-time FTIR, 1 H NMR, and GPC, which confirmed the conversion of styrene and formation of PUPS block copolymer. The influence of reaction temperature on styrene conversion was investigated and the results demonstrated the feasibility of preparation of PUPS block copolymer by UV polymerization at ambient temperature. The DSC and TG data revealed a new glass transition temperature and degradable step respectively for PUPS block copolymer induced by polystyrene block compared with neat polyurethane and polyurethane macrophotoinitiator, which further clarified the formation of PUPS block copolymer. The properties measurements showed that the prepared PUPS block copolymer exhibited better tensile strength, hardness and water-resistance than neat polyurethane.
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高影响因子
AMINO ACIDS
·
2014
·Vol. 46
·期 12
·2681-2691
·
IF 3.653
Ruan Zheng,Yang Yuhui,Wen Yanmei,Zhou Yan,Fu Xiaofang,Ding Sheng,Liu Gang,Yao Kang,Wu Xin,Deng Zeyuan,Wu Guoyao,Yin Yulong
Tryptophan (TRP) is an important precursor for several neurotransmitters and metabolic regulators, which play a vital role in regulating nutrient metabolism. The purpose of this study was to investigate the effects of tryptophan supplementation on the biochemical profiles, intestinal structure, liver structure and serum metabolome in rats. Rats received daily intragastric administration of either tryptophan at doses of 200 mg/kg body weight per day or saline (control group) for 7 days. TRP supplementation had a tendency to decrease the body weight of rats ( P > 0.05). The levels of urea and CHO in serum were decreased in the TRP-supplemented group rats compared with control group rats ( P < 0.05). TRP supplementation increased the villus height and the ratio of villus height to crypt depth in the jejunum compared to control group rats ( P < 0.05). Metabolic effects of tryptophan supplementation include: (1) increases in the serum concentrations of lysine, glycine, alanine, glutamate, glutamine, citrulline, methionine, tyrosine, 1-methylhistidine, and albumin, and decreases in the concentrations of serum branched-chain amino acid (isoleucine, valine and leucine); (2) decreases in the serum concentrations of formate and nitrogenous products (trimethylamine, TMAO, methylamine and dimethylamine), and in the contraction of trimethylamine in feces; (3) decreases in serum levels of lipids, low density lipoprotein, very low density lipoprotein, together with the elevated ratio of acetoacetate to β-hydroxybutyrate. The results indicate that tryptophan supplementation reduced the catabolism of dietary amino acids and promoted protein synthesis in rats, promoted the oxidation of fatty acid and reduced fat deposition in the body of rats.
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PubMed
高影响因子
CHROMATOGRAPHIA
·
2013
·Vol. 76
·期 7
·409-417
·
IF 1.437
Li Chenyu,Chen Ligang
A simple and fast method based on magnetic separation for extraction of pyrethroid pesticides including beta-cyfluthrin, cyhalothrin and cyphenothrin from environmental water samples has been established. Magnetic titanium dioxide was used as sorbent, which was synthesized by coating TiO 2 on Fe 3 O 4 in liquid-state co-precipitation method. The sorbent has been characterized by scanning electron microscopy and Fourier-transform infrared spectrometry, and the magnetic properties were investigated with physical property measurement system. Various parameters affecting the extraction efficiency were evaluated to achieve optimal condition and decrease ambiguous interactions. The analytes desorbed from the sorbent were detected by high performance liquid chromatography. Under the optimal condition, the linearity of the method is in the range of 25–2,500 ng L −1 . The detection limits and quantification limits of pyrethroid pesticides are in the range of 2.8–6.1 ng L −1 and 9.3–20.3 ng L −1 , respectively. The relative standard deviations of intra- and inter-day tests ranging from 2.5 to 7.2 % and from 3.6 to 9.1 % were obtained. In all three spiked levels (25, 250 and 2,500 ng L −1 ), the recoveries of pyrethroid pesticides were in the range of 84.5–94.1 %. The proposed method was successfully applied to determine pyrethroids in three water samples. Cyphenothrin was found in one river water near farmlands, and its concentration was 52 ng L −1 .
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高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2012
·Vol. 15
·期 1
·1-11
·
IF 3.287
Wang Yuanfeng,Xu Feng,Zhang Lei,Wei Xinlin
A one-step strategy for the facile synthesis of polyethyleneimine-functionalized Fe 3 O 4 (Fe 3 O 4 -PEI) composite is presented in this study. We also investigated the effects of reaction time and NaAc on the composite sizes. The composite with good dispersion, wonderful crystallization, and excellent magnetism was obtained through one-pot solvothermal reaction. In the sequential presence of PEI and colloidal gold (Au) solution, plentiful Au nanoparticles with a diameter of 5 nm were assembled on the surface of Fe 3 O 4 –PEI to get Fe 3 O 4 –PEI–Au 1 –PEI–Au 2 (Fe 3 O 4 /Au) composite. In-depth characterization of the composite formation process was performed using transmission electron microscopy, scanning electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, and UV–Visible spectroscopy. The Fe 3 O 4 /Au composite was obtained with an average diameter of 150 nm, and the absorption peak was red-shifted to 580 nm. The synthesized Fe 3 O 4 /Au composite, the saturation magnetization of which was 40.4 emu/g, presented good magnetic property. Moreover, the composite could easily combine with up to 890 μg antibodies per mg, and the antibodies still kept good immunocompetence after immobilization. These advantages suggest its great potential for applications in vitro, such as separation and immunoassay.
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高影响因子
CHROMATOGRAPHIA
·
2015
·Vol. 78
·期 11
·833-837
·
IF 1.411
Zhang Mingyu,Qiu Danye,Kang Jingwu
A simple, sensitive and environmentally friendly capillary electrophoresis method for the determination of free sulfate anions in heparin and low-molecular-weight heparin with indirect UV detection is reported. The background electrolyte consists of 20 mM nitrate (pH 5.5) containing 0.2 mM CTAB. The use of nitrate as the probe anion is based on the consideration that nitrate has a very close electrophoretic mobility to that of sulfate, leading to a very narrow peak shape. Moreover, the apparent molar absorptivity of nitrate at 202 nm (8413 L mol −1 cm −1 ) is much higher than that of the commonly used probe anion chromate at 254 nm (2400 L mol −1 cm −1 ). The combination of the narrow peak shape with the high apparent molar absorptivity of the probe ion improved the limit of detection by 2.4 times and the limit of quantitation by 3.2 times. The effect of various CE parameters on the separation of sulfate from chloride was investigated and optimized. The method displays linearity in the range from 0.05 to 20 mM. The RSD % for intraday ( n = 6), and interday ( n = 3) repeatability in terms of migration times and peak areas were all less than 3 %. The limit of detection ( S / N = 3) and limit of quantitation ( S / N = 10) for sulfate were determined as 18 and 53 µM, respectively. The method was successfully applied for the quantification of sulfate anions in heparin and low-molecular-weight heparins.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 50
·期 5
·2158-2166
·
IF 2.305
Ma Yanli,He Ling,Pan Aizhao,Zhao Chengben
The novel latex of P(GMA-POSS)- co -PMMA is synthesized for coatings by glycidyl methacrylate polyhedral oligomeric silsesquioxane (GMA-POSS) and methyl methacrylate (MMA). First, GMA-POSS is prepared by the epoxide opening reaction of glycidyl methacrylate (GMA) and aminopropyllsobutyl POSS (NH 2 -POSS). Then, the as-obtained GMA-POSS monomer is directly used for emulsion polymerization with MMA to obtain P(GMA-POSS)- co -PMMA latex. The chemical structure of P(GMA-POSS)- co -PMMA latex is characterized. The core–shell morphology of latex is proved to distribute uniform spherical particles as 20–60 nm in diameter. The effect of POSS content on the properties of film casting from P(GMA-POSS)- co -PMMA latex is studied for surface roughness, static contact angle, thermostability, and universal mechanical testing. The introducing of POSS into latex leads to an increase of P(GMA-POSS)- co -PMMA in the hydrophobicity, adhesive strength, thermal and mechanical proprieties. When GMA-POSS amount is controlled at 33 wt%, the glass transition temperature ( T
g ) and static contact angle are increased into 130 °C and 102º, respectively, and the adhesion to the substrate is raised to 477.2 MPa. Therefore, P(GMA-POSS)- co -PMMA is promising to be suggested as coating material.
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高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2015
·Vol. 121
·期 1
·193-202
·
IF 1.704
Lü Mengyun,Guan Tengpeng,Li Ai-Hua,Sun Zhijun
In solvothermal synthesis of Er 3+ -doped NaGd 1− x
Yb
x
F 4 nanocrystals, morphology of the nanoparticles is dependent on the molar ratio of the chelating agent (e.g., trisodium citrate) to the lanthanide ions. Usually, addition of chelating agent is reported to be effective only when the molar ratio is below a critical value usually around 1 for the preparation of Er 3+ - and Yb 3+ -doped NaYF 4 nanocrystals. In this work, we found that, by increasing the Yb 3+ concentration, the critical molar ratio can be up to more than 4 in the preparation of Er 3+ -doped NaGd 1− x
Yb
x
F 4 nanocrystals, which provides a new route to control the nanoparticles’ size. The result is particularly useful for the synthesis of small Er 3+ -doped NaGd 1− x
Yb
x
F 4 nanocrystals with high concentration of the Yb 3+ dopant. We also investigated mechanisms on the formation of such particles ( β -NaGd 0.3 Yb 0.7 F 4 :Er 3+ ) with large size in a sub-micrometer scale, i.e., the aggregation-induced crystal growth. In addition, upconversion luminescence properties of the powdery samples were studied, which is shown to be dependent both on size of the nanoparticles and on dosage of the trisodium citrate.
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高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2015
·Vol. 52
·期 12
·8336-8342
·
IF 2.203
Sun Yujing,Zhong Liezhou,Cao Lianfei,Lin Wenwen,Ye Xingqian
Enzyme browning is the main challenge in the preparation of fresh apple juice. The influence of sonication on browning, as well as polyphenols and antioxidant activity of fresh apple juice was investigated. It was found that ultrasound can inhibit the browning of fresh apple ( Malus pumila Mill , cv. Red Fuji ) juice, but decreased the contents of total phenolic content (TPC), total flavonoid content (TFC) and chlorogenic acid and reduced the antioxidant activity. On the whole, ultrasound technology cannot be used to the antibrowning of fresh apple ( Malus pumila Mill , cv. Red Fuji ) juice.
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PubMed
高影响因子
COLLOID AND POLYMER SCIENCE
·
2015
·Vol. 293
·期 9
·2625-2634
·
IF 1.865
Li Ping,Yang Xiaoyi,Guo Chaohua,Wang Guoyong,Zhang Wei
The adsorption and aggregation behavior of three tetrasiloxane surface active room temperature ionic liquids, N -(2-aminoethyl)-3-aminopropyltetrasiloxane carboxylic acid ammonium, [Si(4)N(2)-2CA(n) ( n = 1, 2, 3)], have been studied on the basis of static/dynamic surface tension, conductivity, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The static surface tension of the Si(4)N(2)-2CA(n) aqueous solutions measured at the critical aggregation concentration (CAC) is observed to be significantly lower than that of amide-functionalized ILs and is comparable to those reported for trisiloxane RT-SAILs, N -(2-aminoethyl)-3-aminopropyltrisiloxane carboxylic acid ammonium and 3-aminopropyltrisiloxane carboxylic acid ammonium. The dynamic surface tension results indicate that adsorption process is a mixed diffusion-kinetic adsorption mechanism. DLS and TEM analysis of Si(4)N(2)-2CA(n) solutions reveal that they can self-assemble into vesicles with an average diameter in the range of 70–500 nm.
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