FLUID PHASE EQUILIBRIA
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2015
·
IF 2.2
Yanni Du,Haiyang Wang,Shichao Du,Yan Wang,Cui Huang,Yujia Qin,Junbo Gong
In this study, the liquid–liquid phase separation and crystallization of vanillin from 1-propanol/water solution were investigated. It was found that water could contribute to the improvement of vanillin solubility in 1-propanol/water solution, but the solubility of vanillin decreased with the increasing water/1-propanol ratios, when the water content was over 30 wt.%. High water fraction in 1-propanol/water solvents will result in the liquid–liquid phase separation in the crystallization process , and the liquid–liquid phase separation dominated the process before the nucleation of crystals during the crystallization of vanillin. A ternary phase diagram (vanillin/1-propanol/water) including the solubility curves and the liquid–liquid phase separation curves was measured and could, in certain cases, clearly illustrate the liquid–liquid phase separation and crystallization process of vanillin in 1-propanol/water solutions. As shown in the ternary phase diagram, liquid–liquid phase separation under high initial vanillin concentration results in low purity of vanillin crystals due to the inhibited crystallization process by liquid–liquid phase separation. Partial phase immiscibility was a function of temperature and the range of immiscibility decreased with increasing temperature. Moreover, nucleation and crystal growth of vanillin in the presence of liquid–liquid phase separation were investigated; process parameters such as the composition of solvent, cooling profiles and seeding were optimized to avoid liquid–liquid phase separation and thus increase the purity of crystallization products.
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Scientific Reports
·
2014
·Vol. 4
·期 1
·1-7
·
IF 5.078
Parhira Supawadee,Zhu Guo-Yuan,Jiang Ren-Wang,Liu Liang,Bai Li-Ping,Jiang Zhi-Hong
Two stereoisomeric cardenolides, uscharin (1) and a new compound, 2′- epi -uscharin (2), were isolated from the latex of Calotropis gigantea (Asclepiadaceae). Their structures were fully elucidated based on their spectroscopic data, X-ray crystallographic data and chemical evidences. Both epimers (1 and 2) exhibited strong inhibitory effects on HIF-1 activity with different magnitudes. Compound 1 showed much more potent activity than 2 and digoxin, a well-known HIF-1 inhibitor. Discrepancy in potencies between 1 and 2 revealed the contribution of a β-configuration of 2′ hydroxyl moiety for HIF-1 inhibitory activity. This is a first report of the activity of HIF-1 inhibition of thiazoline ring-containing cardenolides.
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CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Jiale Huang,Cheng Liu,Daohua Sun,Yingling Hong,Mingming Du,Tareque Odoom-Wubah,Weiping Fang,Qingbiao Li
Au/TS-1 catalysts prepared by an eco-friendly and economical bioreduction method were used for the liquid phase epoxidation of styrene to styrene oxide (SO) using aqueous hydrogen peroxide (H 2 O 2 ) as oxidant. The catalysts were characterized by a variety of techniques including FT-IR, DRUV–Vis, UV–Vis, N 2 physisorption, XRD, XPS, TG–DTG and TEM. The influence of various parameters (Au loading, calcination, solvents, oxidants, reaction temperature, reaction time and catalyst amount) on the catalytic performance was systematically investigated. The results showed that both the conversion of styrene and selectivity to SO were improved and enhanced when catalyzed by biosynthesized gold nanoparticles (GNPs) supported on TS-1. However, decomposing the Cacumen Platycladi ( CP ) biomass properly through calcinations can enhance the catalytic performance though it acted as reductant and protective agents during the catalysts preparation. Besides, the optimum catalytic activity and stability of bioreduction Au/TS-1 catalysts were obtained under operational conditions of Au loading of 1.0 wt.%, CP extract (10 g L −1 ) as reductant, calcined at 723 K for 2 h, reaction time of 10 h, reaction temperature of 333 K, catalyst amount of 500 mg, aqueous H 2 O 2 (30 wt.%) as oxidant and N,N-dimethylformamide as solvent. Under the optimal condition, styrene conversion of 92.7% and SO selectivity of 90.4% was achieved, which were comparable or even superior to those reported in the literatures. The catalyst was reused five times, without significant decrease in both the styrene conversion and SO selectivity.
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CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
C. Shen,Y.J. Wang,C. Dong,G.S. Luo
In this work, porous glass beads supported with TS-1 particles have been successfully prepared through in situ crystallization. TS-1 particles with uniform size and high crystallization are well dispersed on the surface of porous glass beads. As the support, porous glass beads exhibit the advantages of more manageable surface chemistry, better chemical and thermal stability, and larger specific surface area compared to that of conventional TS-1 films on flat or tubular supports. The experimental results show that the surface chemistry has profound influence on the morphology of TS-1 particles. The catalytic performance of the material was characterized with the reaction of ammoximation of cyclohexanone. Complete conversion was reached after 20 min in a stirred tank reactor with the selectivity of 100%. Compared with the commercial catalyst, the reaction rate was increased by 54 times. The prepared catalysts were packed in a bed reactor, and the effects of space time, content of catalyst, temperature and pressure were investigated. The conversion of 48.1% was reached by the catalyst with TS-1 loading of 0.183 wt.% at 353 K and the space time of only 1.57 min, and 100% recovery in catalytic activity after 5 cycles was demonstrated.
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RSC Advances
·
2015
·Vol. 5
·期 41
·32416-32420
·
IF 3.84
Kang Qin,Kai Wang,Yang Li,Fanhe Kong,Tao Wang
The phase behavior of the 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) and carbon dioxide (CO2) system from atmospheric to supercritical state was investigated at 0.1–15.0 MPa and 308.15–343.15 K. The solubility data of CO2 in [emim][BF4] and the volumetric expansion ratios of CO2-saturated [emim][BF4] were provided. Experimental results indicated that although CO2 dissolved significantly in [emim][BF4] (from 0 to 62 mol%), the ionic liquid phase only had an expansion ratio less than 17 vol%. The density difference between CO2-saturated [emim][BF4] and pure [emim][BF4] was obvious at high pressure and low temperature, with a maximum of 16.11% at 308.15 K and 15.0 MPa. Based on the experimental results, a fitting equation applicable to precise data interpolation was proposed for the CO2-saturated [emim][BF4] density in this study.
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JOURNAL OF MOLECULAR LIQUIDS
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2014
·
IF 2.083
Jiayi Chen,Lingxiao Chen,Yueqing Lu,Yingjie Xu
Densities ( ρ ) and viscosities ( η ) of 1-methylimidazolium acetate ([Mim]Ac) protic ionic liquid + water mixture were measured at T = (293.15, 298.15, 303.15, 308.15 and 313.15) K under atmospheric pressure. Refractive indices ( n D ) and electrical conductivities ( κ ) of the above-mentioned system over the entire composition range were measured at 298.15 K. Excess molar volumes ( V E ), viscosity deviations (Δ η ) and refractive index deviations (Δ n D ) were obtained from the experimental data and fitted to the Redlich–Kister equation with satisfactory results. The results show that V E values of the system are negative over the whole composition range, whereas Δ η and Δ n D values are positive. Other volumetric properties such as apparent molar volumes ( V ϕi ), partial molar volumes ( V ¯ m , i ) and excess partial molar volumes ( V ¯ m , i E ) of the system were calculated from the density data. The concentration dependence of κ was fitted according to the empirical Casteel–Amis equation. The measured and derived properties were employed to investigate the intermolecular interactions of the system.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2016
·
IF 8.328
Xuyang Xiong,Liyong Ding,Qingqian Wang,Yongxiu Li,Qingqing Jiang,Juncheng Hu
A series of BiOBr nanosheets with tunable exposing proportion of (0 1 0) facets had been synthesized. In the synthesis process, different n -alcohols are used, which not only promote the exposure of (0 1 0) facets, but also modulate the size and thickness of these BiOBr nanosheets in a wide range. Furthermore, these nanosheets showed an efficient photodegradation activity for salicylic acid (SA) and Rhodamine B (RhB). By comparison, the sample prepared in n -hexanol possessed the highest photocatalytic activity than those synthesized in n -butanol and methanol, respectively. This excellent photocatalytic activity was attributed to the thin lamellar thickness and the exposure of (0 1 0) facets, which facilitated the separation of photoinduced electrons and holes.
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2016
·
IF 3.902
Lin Li,Xingsheng Di,Shenwu Zhang,Qiming Kan,Hao Liu,Tianshu Lu,Yongjun Wang,Qiang Fu,Jin Sun,Zhonggui He
The therapeutic outcome of glioma treatment is rigorously limited by blood–brain barrier (BBB) and infiltrating growth of glioma. To tackle the dilemma, more and more attentions were focused on developing nutrient transporters-mediated dual-targeted drug delivery system, in one side for BBB penetration, another for intracranial glioma targeting. Herein, Large amino acid transporter 1 (LAT1), overexpressed both on BBB and glioma cells, was selected as a target. Docetaxel-loaded glutamate- d -α-tocopherol polyethylene glycol 1000 succinate copolymer (Glu-TPGS) functionalized LAT1-targeting liposomes (DTX-TGL) were applied to enhance the BBB penetration and glioma therapy. The in vivo results of the fluorescent image indicated that TGL possessed an effective BBB penetration than that of unmodified ones in mice. The LAT1 targeting effcicacy and cell cytotoxicity of TGL were investigated in C6 glioma cells. Compared with unmodified liposomes, a significant higher cellular uptake and cell cytotoxicity was found in TGL treated group. Our results indicated that LAT1-targeting docetaxel-loaded liposome paves up a new direction using LAT1 transporter as a good target in designing brain glioma-targeting nanosystems.
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Cell Death & Disease
·
2017
·Vol. 8
·期 2
·e2609
·
IF 5.965
Yang Mengliu,Wang Jinzhi,Wu Shaobo,Yuan Lei,Zhao Xiaodong,Liu Chaohong,Xie Jing,Jia Yanjun,Lai Yerui,Zhao Allan Zijian,Boden Guenther,Li Ling,Yang Gangyi
Intestinal glucagon-like peptide-1 (GLP-1) is a hormone that stimulates insulin secretion and acts as a neuropeptide to control glucose homeostasis, but little is known whether intestinal GLP-1 has any effect in the control of hepatic glucose production (HGP). Here we found that intraduodenal infusion of GLP-1 activated duodenal PKC- δ , lowered HGP and was accompanied by a decrease in hepatic expression of gluconeogenic enzymes and an increase in hepatic insulin signaling in rats. However, gut co-infusion of either the GLP-1 receptor antagonist Ex-9, or the PKC- δ inhibitor rottlerin with GLP-1, negated the ability of gut GLP-1 to lower HGP and to increase hepatic insulin signaling during clamps. The metabolic and molecular signal effects of duodenal GLP-1 were also negated by co-infusion with tetracaine, pharmacologic inhibition of N -methyl- d -aspartate receptors within the dorsalvagal complex, or hepatic vagotomy in rats. In summary, we identified a neural glucoregulatory function of gut GLP-1 signaling.
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PHYTOMEDICINE
·
2016
·
IF 2.937
Ramachandran Vinayagam,Baojun Xu
Background and objective Daphnetin (7, 8-dihydroxycoumarin), a natural coumarin compound, is known to exhibit antioxidant and anti-inflammatrory effects. However, the underlying mechanisms of its anti-apoptotic and antidiabetic effects yet not been examined. Therefore, the present work studied the anti-apoptotic and anti-diabetic effects of daphnetin by in vitro experiments. Methods The rat insulinoma (INS-1) cells were pre-treated with daphnetin at different concentrations (1, 10, 20 and 40 µM) for 24 h followed by exposition to streptozotocin (STZ) (3 mM) for 12 h. Effects of daphnetin and STZ on INS-1 cells were determined by MTT assay, glucose stimulated insulin secretion (GSIS) assay, lipid peroxidation, antioxidant status (SOD, CAT, GPx, and GST) Apoptosis staining (DAPI, Hoechst 33342, AO/EB and ROS) was performed by fluorescence microscopy, and Bcl-2, Bax and NF-κB protein expression was detected by Western blotting. Results MTT assay indicated that the viability of INS-1 cells was significantly reduced with exposure to STZ for 12 h as compared to control cells, while pre-treated with daphnetin for 24 h resulted in a significant improvement of cell viability. The effects daphnetin treatment in INS-1 cells on insulin secretion was tested and results showed that the pre-treatment of daphnetin could improve GSIS. Further, daphnetin pre-treatment significantly reduced the levels of lipid peroxidation markers and also improved antioxidant enzymes’ activities in STZ-induced INS-1 cells. Western blotting assay revealed that daphnetin could suppress apoptosis through up-regulation of anti-apoptotic Bcl-2 protein expression and the down-regulation of pro-apoptotic Bax and nuclear factor NF-κB protein levels. Conclusion The results showed that daphnetin might be used in treating diabetes due to its insulin stimulating property and subsequent regulation of apoptotic pathway.
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JOURNAL OF MEMBRANE SCIENCE
·
2016
·
IF 5.557
Dong Guo,Yi Zhi Zhuo,Ao Nan Lai,Qiu Gen Zhang,Ai Mei Zhu,Qing Lin Liu
There is a balance between ionic conductivity and dimensional stability in anion exchange membranes (AEMs). High conductivity resulting from densely charged groups is normally accompanied with high water uptake and excessive swelling. Herein, a series of novel AEMs with interpenetrating network was prepared by the incorporation of poly(vinylbenzyl chloride) (PVBC) and poly(1-vinylimidazole)(PVIm) into the PVA matrix. PVBC and PVIm act as bifunctional macromolecular crosslinking agents to provide both imidazolium cations and to form crosslinked network in the membranes. The resulting AEMs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The effect of crosslinking density on conductivity, water uptake, swelling ratio and stability was investigated. The results reveal that the addition of PVBC-c-PVIm could be simultaneously conducive to higher conductivity and lower swelling ratio. Notably, the membrane containing 50 wt% PVBC-c-PVIm had IEC of 1.86 meq g −1 , water uptake of 39.4%, and hydroxide conductivity of 21.9 mS cm −1 at 30 °C. A maximum power density of 37.1 mW cm −2 is achieved at a current density of 64 mA cm −2 . The crosslinked AEMs also exhibit excellent alkaline stability in a 4 M KOH solution at 60 °C for 1320 h.
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Nanoscale Research Letters
·
2016
·Vol. 11
·期 1
·1-8
·
IF 2.584
Zheng Dan,Guo Peng,Xiong Juan,Wang Shengfu
A ZnO-based film bulk acoustic resonator has been fabricated using a magnetron sputtering technology, which was employed as a biosensor for detection of mucin 1. The resonant frequency of the thin-film bulk acoustic resonator was located near at 1503.3 MHz. The average electromechanical coupling factor \( {K}_{\mathrm{eff}}^2 \) and quality factor Q were 2.39 % and 224, respectively. Using the specific binding system of avidin-biotin, the streptavidin was self-assembled on the top gold electrode as the sensitive layer to indirectly test the MUC1 molecules. The resonant frequency of the biosensor decreases in response to the mass loading in range of 20–500 nM. The sensor modified with the streptavidin exhibits a high sensitivity of 4642.6 Hz/nM and a good selectivity.
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