JOURNAL OF POROUS MATERIALS
·
2014
·Vol. 21
·期 5
·739-746
·
IF 1.316
Guo Li,Zhang Ran,Zhao Xiuge,Gan Huimei,Song Baoning,Chen Jizhong,Zhu Wenwen,Hua Li,Hou Zhenshan
Mesoporous silica materials were prepared by infusion and selective condensation of silicon alkoxides within self-assembly formed from protonated hexadecylamine by CO 2 in aqueous media. Compared to the conventional synthesis approach, the introduction of CO 2 facilitates the hydrolysis of silicon alkoxide precursor and does not need adding any co-solvent in the course of the synthesis of mesoporous material. Moreover, CO 2 can be used as a swelling agent increasing the average pore size form 3.2–5.4 nm with expansion rate of approximately 69 %. The influence of CO 2 pressure and temperature were carefully investigated. During the preparation, nonionic surfactant hexadecylamine can turn into cationic surfactant in situ as mesostructure-directing template under pressurized CO 2 condition, which is the key factor for the formation of ordered mesoporous silica. In addition, the supported Pd catalysts were prepared and characterized thoroughly by X-ray diffraction, 1 H NMR, 13 C NMR, ICP-AES analysis, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption measurements. On the basis of the characterization and hydrogenation performance of the catalysts, the roles of different supports were discussed.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 21
·12563-12568
·
IF 2.757
Shen Shuguang,Li Meina,Li Binbin,Zhao Zhijun
In order to find an effective method for treating urea wastewater, the experiments on the hydrolysis of urea in wastewater were conducted in a fixed bed reactor with different aluminas (α-Al 2 O 3 , γ-Al 2 O 3 , and η-Al 2 O 3 ) as catalysts respectively in contrast with inert ceramic particle. The results indicate that the three alumina catalysts show obvious catalytic activity for urea hydrolysis at 125 °C. The order of activity is η-Al 2 O 3 > γ-Al 2 O 3 > α-Al 2 O 3 , and the activity difference increases with increasing temperature. According to the characterization results, surface acidity has little impact on the activity of catalyst. However, it was found that surface basicity of alumina catalyst plays an important role in catalytic hydrolysis of urea, and the activity of catalyst may be also influenced by the basic strength. With η-Al 2 O 3 as catalyst, the urea concentration in wastewater is reduced to 4.96 mg/L at a temperature of 165 °C. Moreover, the η-Al 2 O 3 shows a good stability for urea hydrolysis. The hydrolysis of urea over η-Al 2 O 3 catalyst can evidently reduce the reaction temperature and is promising to replace industrial thermal hydrolysis process.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2014
·Vol. 18
·期 10
·2743-2753
·
IF 2.234
Li Meng,Jiang Li-Qing,Lin Lin,Li Yong-Feng,Yu Ding-Ling,Cui Li-Li,He Xing-Quan
A novel high-performance non-noble metal electrocatalyst for the oxygen reduction reaction (ORR) was fabricated by anchoring cobalt tetraferrocenylporphyrin (CoFcP) onto poly(sodium- p -styrenesulfonate) modified graphene (PSS-Gr) through solvothermally assisted π–π assembling method. The morphology of the assembled composite was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The interactions between CoFcP moieties and graphene sheets were confirmed by UV–Vis absorption spectroscopy and X-ray photoelectron spectroscopy. The electrocatalytic properties of the CoFcP/PSS-Gr catalyst towards the oxygen reduction reaction were assessed using rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) measurements in both alkaline and acidic media. In addition, cyclic voltammetry and chronoamperometric measurements were utilized to evaluate the catalytic activity and stability of the CoFcP/PSS-Gr composite in alkaline solution. The results showed that CoFcP supported on graphene exhibited an outstanding electrocatalytic performance towards the ORR comparable with commercial Pt/C catalyst in alkaline media, such as high onset potential (0.889 V vs. reversible hydrogen electrode, RHE), half wave potential (0.789 V vs. RHE), better tolerance to methanol, excellent stability (84.1 %, retention after 10000 s), and efficient four-electron pathway. Moreover, the proposed hybrid presented excellent catalytic activity in terms of onset potential (0.72 V vs. RHE) and high-electron transfer number compared with Pt/C in acidic media.
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JOURNAL OF POLYMER RESEARCH
·
2014
·Vol. 21
·期 7
·1-7
·
IF 1.897
Chang Ruixue,Qin Jianglei,Gao Jungang
In this study, isosorbide diglycidyl ether (isosorbide epoxy) was cured by a
variety of biobased curing agent of terpene maleic anhydride (TMA) and maleopimaric
acid (MPA) to prepare fully biobased epoxy resins. The structures of isosorbide
epoxy and biobased curing agents were synthesized and characterized by NMR. The
non-isothermal curing kinetics of fully biobased epoxies were studied using
differential scanning calorimetry (DSC). The bis-phenol A type epoxy and petroleum
based curing agent methyl Nadic anhydride (MNA) bearing similar caged structure was
also studied for comparison. The mechanical properties of the biobased epoxy resins
were evaluated using dynamic mechanical analysis (DMA) and the thermal stability was
characterized by thermogravimetric analysis (TGA), respectively. The fully biobased
epoxies have comparable or even better mechanical properties and thermal stability
than the biophenol A type epoxies cured by petroleum based curing agents, showing
that the biobased isosorbide epoxies have great potential application as substitute
for those petroleum based epoxies.
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FIBERS AND POLYMERS
·
2014
·Vol. 15
·期 5
·938-942
·
IF 1.113
Zhu Chao,Lin Junxiong,Wang Lan
Photoactive blend films consisting of sulfonated polyether ether ketone and polyvinyl alcohol were incorporated onto cotton fibers to prepare self-decontaminating cotton fabrics. Electron paramagnetic resonance (EPR) spectroscopy was used to confirm the free-radical nature of the photoactive film and the cotton fabric. Several physical and mechanical properties of the fabrics, such as surface morphology, tensile strength, softness, whiteness, and water vapor permeability, were investigated, and it was found that the treated cottons basically maintained the original performance. Moreover, favorable photo-induced self-decontaminating capabilities of the treated fabrics were demonstrated against three kinds of pollutants, including decomposition of 80.2 % diuron under UVA light irradiation for 3 hours, inactivation of 93.33 % of E.coli and 86.67 % of S.aureus , and degradation of 64.1 % methyl orange under the light irradiation for 1 hour.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2014
·Vol. 406
·期 20
·4987-4995
·
IF 3.578
Fu Yu,Mo Hua-Yan,Gao Wen,Hong Jia-Ying,Lu Jun,Li Ping,Chen Jun
Xanthine oxidase (XOD) is a key oxidative enzyme to the pathogenesis of hyperuricemia and certain diseases induced by excessive reactive oxygen species. XOD inhibitors could provide an important therapeutic approach to treat such diseases. A new method using affinity selection-based two-dimensional chromatography coupled with liquid chromatography-mass spectrometry was developed for the online screening of potential XOD inhibitors from Radix Salviae Miltiorrhizae. Based on our previous study, the two-dimensional, turbulent-flow chromatography (TFC) was changed to a mixed-mode anion-exchange/reversed-phase column and one reversed-phase column. The developed method was validated to be selective and sensitive for screening XOD-binding compounds, especially weak acidic ones, in the extracts. Three salvianolic acids were screened from the Radix Salviae Miltiorrhizae extract via the developed method. The XOD inhibitory activities of salvianolic acid C and salvianolic acid A were confirmed, and their inhibitory modes were measured. Salvianolic acid C exhibited potent XOD inhibitory activity with an IC 50 of 9.07 μM. This work demonstrated that the developed online, two-dimensional TFC/LC-MS method was effective in discovering the binding affinity of new compounds from natural extracts for target proteins, even at low concentrations.
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Nanoscale Research Letters
·
2014
·Vol. 9
·期 1
·1-10
·
IF 2.481
Li Chen,Wang Zhuan-Hua,Yu Deng-Guang,Williams Gareth R
This manuscript reports a new type of drug-loaded core-shell nanofibers that provide tunable biphasic release of quercetin. The nanofibers were fabricated using a modified coaxial electrospinning process, in which a polyvinyl chloride (PVC)-coated concentric spinneret was employed. Poly (vinyl pyrrolidone) (PVP) and ethyl cellulose (EC) were used as the polymer matrices to form the shell and core parts of the nanofibers, respectively. Scanning and transmission electron microscopy demonstrated that the nanofibers had linear morphologies and core-shell structures. The quercetin was found to be present in the nanofibers in the amorphous physical status, on the basis of X-ray diffraction results. In vitro release profiles showed that the PVP shell very rapidly freed its drug cargo into the solution, while the EC core provided the succedent sustained release. Variation of the drug loading permitted the release profiles to be tuned.
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Nanoscale Research Letters
·
2014
·Vol. 9
·期 1
·1-13
·
IF 2.481
Li Chao,Ji Yang,Wang Can,Liang Shujing,Pan Fei,Zhang Chunlei,Chen Feng,Fu Hualin,Wang Kan,Cui Daxiang
Successful development of safe and highly effective nanoprobes for targeted imaging of in vivo early gastric cancer is a great challenge. Herein, we choose the CdSe/ZnS (core-shell) quantum dots (QDs) as prototypical materials, synthesized one kind of a new amphiphilic polymer including dentate-like alkyl chains and multiple carboxyl groups, and then used the prepared amphiphilic polymer to modify QDs. The resultant amphiphilic polymer engineered QDs (PQDs) were conjugated with BRCAA1 and Her2 monoclonal antibody, and prepared BRCAA1 antibody- and Her2 antibody-conjugated QDs were used for in vitro MGC803 cell labeling and in vivo targeted imaging of gastric cancer cells. Results showed that the PQDs exhibited good water solubility, strong photoluminescence (PL) intensity, and good biocompatibility. BRCAA1 antibody- and Her2 antibody-conjugated QD nanoprobes successfully realized targeted imaging of in vivo gastric cancer MGC803 cells. In conclusion, BRCAA1 antibody- and Her2 antibody-conjugated PQDs have great potential in applications such as single cell labeling and in vivo tracking, and targeted imaging and therapeutic effects' evaluation of in vivo early gastric cancer cells in the near future.
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JOURNAL OF MEMBRANE BIOLOGY
·
2017
·Vol. 250
·期 5
·483-492
·
IF 1.696
Chai Ran,Chen Yafei,Yuan Hongbo,Wang Xuzhao,Guo Shuai,Qi Jinlong,Zhang Hailin,Zhan Yong,An Hailong
Calcium-activated chloride channels (CaCCs) play vital roles in a variety of physiological processes. Dysfunction of the CaCCs is implicated in many diseases. Drug discovery targeting at CaCCs has recently become possible with the determination that TMEM16A is the molecular identity of CaCCs. In this study, we demonstrated that resveratrol (RES), a Chinese traditional medicine compound, is a novel activator of TMEM16A. The yellow fluorescence protein quenching assay and measurement of intracellular calcium fluorescence intensity show that RES activates TMEM16A channels in an intracellular Ca 2+ -independent way. The data of inside-out patch clamp revealed that RES dose-dependently activates TMEM16A (EC 50 = 47.92 ± 9.35 μM). Furthermore, RES enhanced the contractions of the ileum of guinea pigs by activating the TMEM16A channel, which indicated that RES might be a promising drug for the treatment of gastrointestinal hypomotility. As RES was able to induce TMEM16A channel activation, TMEM16A can be added to the list of RES drug targets.
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CELLULOSE
·
2017
·Vol. 24
·期 11
·5025-5040
·
IF 3.417
Lin Fengcai,You Yuzhe,Yang Xuan,Jiang Xin,Lu Qilin,Wang Ting,Huang Biao,Lu Beili
A facile, green and efficient microwave-assisted method was developed to oxidize cellulose hydrogel beads with neutral 2,2,6,6-tetramethylpiperidinyl-1-oxyl radical (TEMPO)-mediated system. Resulting cellulose beads were investigated by scanning electron microscopy, solid-state 13 C-NMR spectra, and X-ray diffraction. The patterns of 13 C-NMR spectra indicated that the oxidation occurred only at C6 primary hydroxyl carbon, and the carboxyl groups amounted to 1.28 mmol/g in the cellulose beads. The TEMPO-oxidized cellulose beads showed highly porous structures consisting of nano-sized fibrils with retention of original spherical shapes, and the crystallinity index of the cellulose II almost unchanged after oxidation. The maximum adsorption capacity of rhodamine B, auramine O, malachite green and methylene blue on the TEMPO-oxidized cellulose beads was found to be 609, 537, 740 and 873 mg/g, respectively, and the adsorption process was well described by pseudo-second-order kinetics. In addition, desorption tests showed that TEMPO-oxidized cellulose beads could be regenerated by acid treatment and used repeatedly. Thus, TEMPO-oxidized cellulose beads prepared by microwave irradiation can be potentially used for the removal of organic dyes from industrial wastewater.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2017
·Vol. 19
·期 9
·1-13
·
IF 2.02
Tang Huanfeng,Huang Zaiyin,Xiao Ming,Liang Min,Chen Liying,Tan XueCai
The activities, selectivities, and stabilities of nanoparticles in heterogeneous reactions are size-dependent. In order to investigate the influencing laws of particle size and temperature on kinetic parameters in heterogeneous reactions, cubic nano-Cu 2 O particles of four different sizes in the range of 40–120 nm have been controllably synthesized. In situ microcalorimetry has been used to attain thermodynamic data on the reaction of Cu 2 O with aqueous HNO 3 and, combined with thermodynamic principles and kinetic transition-state theory, the relevant reaction kinetic parameters have been evaluated. The size dependences of the kinetic parameters are discussed in terms of the established kinetic model and the experimental results. It was found that the reaction rate constants increased with decreasing particle size. Accordingly, the apparent activation energy, pre-exponential factor, activation enthalpy, activation entropy, and activation Gibbs energy decreased with decreasing particle size. The reaction rate constants and activation Gibbs energies increased with increasing temperature. Moreover, the logarithms of the apparent activation energies, pre-exponential factors, and rate constants were found to be linearly related to the reciprocal of particle size, consistent with the kinetic models. The influence of particle size on these reaction kinetic parameters may be explained as follows: the apparent activation energy is affected by the partial molar enthalpy, the pre-exponential factor is affected by the partial molar entropy, and the reaction rate constant is affected by the partial molar Gibbs energy.
In situ microcalorimetry, combined with theoretical models, was used to investigate the reaction kinetic parameters of cubic nano-Cu 2 O, and those effects of particle size and temperature were discussed systematically.
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POLYMER BULLETIN
·
2016
·Vol. 74
·期 8
·3109-3121
·
IF 1.371
Sun Wei,Zheng Yan,Zhang Xingyuan
Novel waterborne polyurethane (WPU) with side-chained Phenylazonaphthalene group was prepared by step-growth addition polymerization between isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMG), 2, 2-dimethylol propionic acid (DMPA) and a self-made azo diol, N , N -(2-hydroxyethyl)-4-phenylazo naphthylamine (HPN), as a chain extender to partially substitute for 1, 4-butanediol (BDO). 1 H nuclear magnetic resonance spectra ( 1 H NMR), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet–Visible (UV–Vis) spectroscopy were used to research the properties of HPN and HPN-WPU. The WPU latex presented obvious trans–cis photoisomerization during UV radiation and the absorption wavelength of the HPN exhibited a blue shift after attached into polyurethane chains. It needed longer irradiated time to finish isomerization due to the emulsion aggregated states, comparing with phenylazonaphthalene monomer solution and WPU dilute solution.
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