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Li1.6Mn1.6−xCrxO4 was synthesized by hydrothermal reaction followed by acid leaching to form lithium ion sieve. The structure, morphology and composition were examined using X-ray diffraction, SEM ...

Barium tungstate is one of the important components of complex tungsten minerals and is also an intermediate product of hydrometallurgy. Since it is thermodynamically a very stable mineral, most of the current tungsten ore leaching methods are ineffective for its processing. In addition, due to the high toxicity of barium ions, special attention must be paid during the leaching process. In order to solve these problems, a new method of using sodium sulfate to decompose barium tungstate is proposed in this article. A thermodynamic analysis of the Ba2+-SO42–-WO42–-H2O system is carried out, in which the changes of various ions and precipitations at different pH values and different amounts of sodium sulfate were explored. Moreover, this method is theoretically proved to be feasible. Also, the leaching of barium tungstate experiment was carried out. Under optimum conditions with liquid/solid ratio 10:1 mL/g, reaction temperature 75 °C, and Na2SO4 dosage 2.5–3.0 M times to BaWO4, the leaching rate of barium tungstate was >99%. This method has the advantages of simplicity, and high leaching rate, and it is cost effective with no barium toxicity.

The method for solving inverse heat conduction problems was used to develop a computational model of the heat flux on the high-temperature wall of an engine. The heat flux on the wall surface was calculated from measured temperatures and used as the objective function for the inverse solution. The conjugate gradient method was used to optimize the solution with the differential equations for the heat conduction discretized by the finite element method. A computational method was then developed to solve the inverse problem in a two-dimensional wall. The calculated temperatures agree well with the measured data. The maximum error in the calculated temperatures was 3% even for a sharp change in the heat flux. The corresponding error in the calculated heat fluxes was less than 18%.

This paper presents experimental investigations of the convection heat transfer of n-decane at supercritical pressures in vertical tubes with inner diameters of 0.95 and 2.00 mm for various inlet pressures, heat fluxes and flow directions. The effects of the heat fluxes, property variations, buoyancy and flow acceleration on the convection heat transfer were studied. The results show that for high inlet Reynolds numbers neither buoyancy nor flow acceleration affects heat transfer significantly, while for low inlet Reynolds numbers buoyancy strongly reduces heat transfer coefficient in upward flow cases. The threshold for Bo∗ was found to be about 2.0 × 10−7. Two local Nusselt number correlations for the convection heat transfer of supercritical pressures n-decane with and without buoyancy effect were developed based on the experimental data.

Choriocarcinoma is a malignant trophoblastic tumor. The development of novel drugs is required to reduce the toxicity of current multi-agent chemotherapy and to successfully treat chemoresistant cases of the disease. The purpose of the present study was to investigate the effect of dihydromyricetin (DMY) on the human choriocarcinoma cell line, JAr, to identify a novel drug for the treatment of choriocarcinoma. An MTT assay was performed to determine the effects of DMY at different concentrations and for different exposure durations. Flow cytometry and TUNEL assays were performed to detect apoptosis, and western blotting was utilized to investigate the underlying mechanism. The results revealed that DMY significantly inhibited JAr cell viability in a time- and dose-dependent manner. The flow cytometry and TUNEL assays demonstrated that DMY inhibited proliferation by inducing apoptosis. Further analysis by western blotting indicated that the protein expression level of BCL-2 associated X, associated protein increased, while the protein expression levels of BCL-2 and pro-caspase-3 decreased. These findings suggest that DMY induced apoptosis in human choriocarcinoma JAr cells, through a mitochondrially mediated apoptotic pathway.

Background The role of stress signals in regulating gastric cancer initiation and progression is not quite clear. It is known that stress signals modulate multiple processes such as immune function, cell migration and angiogenesis. However, few studies have investigated the mechanisms of how stress signals contribute to gastric cancer angiogenesis. Methods Here, we used β2-adrenergic receptor (β2-AR) agonist isoprenaline to imitate a stress signal and demonstrated the molecular mechanism underlying stress’s influence on tumor angiogenesis. Results We found that isoprenaline stimulated vascular endothelial growth factor (VEGF) secretion in gastric cancer cells and plexin-A1 expression was induced by human recombinant VEGF165 in both gastric cancer cells and vascular endothelial cells. Furthermore, interfere with plexin-A1 expression in gastric cancer cells influence HUVEC tube formation, migration and tumor growth in vivo. Conclusions These findings suggest that isoprenaline stimulate VGEF secretion and subsequently up-regulate the expression of plexin-A1 and VEGFR2 in gastric cancer cells, which form a positive impetus to promote tumor angiogenesis. This study reveals a novel molecular mechanism that a stress signal like isoprenaline may enhance angiogenesis via activating plexin-A1/VEGFR2 signaling pathway in gastric cancer, which may be a potential target in development of an anti-angiogenic therapy for gastric cancer.

International audience; An efficient protocol is described for producing cyclic carbonates in good to excellent yields under moderate reaction conditions (100.0 °C, 1.0 MPa) by treating epoxides with carbon dioxide, promoted by a series of azolate ionic liquids, which are effective, recyclable, metal-free, and halide-free catalysts.

Recently, chiral ionic liquids (ILs) have drawn increasing attention in chiral separation field; however, few papers reported the application of chiral ILs for chiral separation by capillary electrophoresis (CE), and among the papers, chiral ILs were mainly applied as additives to β-cyclodextrin derivatives systems to establish synergistic systems. The synergistic system based on antibiotics with chiral ILs as additives has never been reported before. In this paper, two chiral ionic liquids (ILs) based on amino acid ester, l -alanine and l -valine tert butyl ester bis (trifluoromethane) sulfonamide, were first applied to evaluate the synergistic effect with antibiotic selector for CE chiral separation. The vancomycin-based synergistic system with chiral ILs as additives was successfully established and investigated for the enantioseparation of naproxen, carprofen, ibuprofen, ketoprofen and pranoprofen. Compared to vancomycin-alone cases, significant improvement of separation for all the analytes was observed. Several parameters, such as type and proportion of organic modifier, composition and pH of buffer, concentration of chiral ILs and vancomycin were systematically investigated, and then evaluated by means of Statistical Product and Service Solutions (SPSS) to research the influences on the synergistic effect. Finally, the established method was successfully applied to test the chiral impurity of naproxen sample.

Turbidity in the one-phase region and the isobaric heat capacity per unit volume in both one-phase and two-phase regions for the critical solutions of {benzonitrile + n-alkane} were measured, from which the values of the system-dependent critical amplitudes for the correlation length, the osmotic compressibility, the heat capacity and the correction-to-scaling term of the heat capacity were deduced. The previously reported data of the coexistence curves for {benzonitrile + n-alkane} were also reanalyzed with the crossover model to obtain the crossover parameters. Subsequently, these results together with the values of the critical amplitude related to the coexistence curve reported previously were used to calculate some universal critical amplitude ratios, which showed reasonable agreement with the theoretical predictions.

(Liquid + liquid) coexistence curve, turbidity, and isobaric heat capacity per unit volume for the critical solution of {benzonitrile + n -undecane} have been measured. The critical exponents β , ν , γ , and α have been deduced, which were found to be consistent with the theoretic predictions. Meanwhile, the experimental data have also been analyzed to obtain the system-dependent critical amplitudes B , ξ 0 , χ 0 , A ± , and D corresponding to the difference of the general density variable of two coexisting phases Δ ρ , the correlation length ξ , the osmotic compressibility χ , the isobaric heat capacity per unit volume C p V −1 , and the first term of correction-to-scaling for the isobaric heat capacity per unit volume, which were used to test some universal ratios. It was found that the coexistence curve may be well described by the crossover model proposed by Gutkowski et al . The critical-fluctuation induced contribution to the background heat capacity B cr was obtained and used to analyze the asymmetric behavior of the diameter of the coexistence curve. The result indicated that the asymmetry of the coexistence curve can be well described by the complete scaling theory proposed by Anisimov et al ., and the heat capacity does make a significant contribution to this asymmetric behavior.

Densities and isobaric heat capacities per unit volume have been measured for binary mixtures {x benzonitrile + (1 − x) octane} and {x benzonitrile + (1 − x) nonane} in the temperature ranges of (283.15 to 318.15) K and (283.15 to 313.15) K, respectively. Measurements covered the whole composition range at the ambient pressure. From these measured data, the excess molar volumes, excess isobaric thermal expansivities, and excess isobaric molar heat capacities were calculated and fitted with the Redlich−Kister equation. The excess molar volumes, excess isobaric thermal expansivities, and excess isobaric molar heat capacities of both systems were found to exhibit the S-shaped curves against the composition and the feature of the nonrandomness mixing. The dependences of these properties on the temperature and composition were analyzed and discussed in terms of the natures of the two pure components and the molecular interactions in the mixtures.

An efficient and greener synthesis of unsymmetrical organic carbonates mediated by Hünig’s base-appended basic ionic liquids, via carbon dioxide conversion, is described here. These ionic liquids were found to be effective bases for the fixation of carbon dioxide by various alcohols and benzyl bromide, at room temperature. When the alcohol and the halide functionalities are present within the same substrate, the reaction cleanly produces a cyclic carbonate. These functionalised basic ionic liquids were fully recyclable with no loss product yields.

The critical behavior of isobaric heat capacities per unit volume for a series of critical binary solutions {benzonitrile + octane, or dodecane, or hexadecane} and {dimethyl carbonate + nonane, or decane, or dodecane} were studied. The corresponding exponent was obtained to be in consistent with the 3D-Ising value. The amplitudes in one-phase and two-phase regions were deduced, which were used to test some critical amplitude ratios. Analysis of the dependence of the effective critical exponent of the heat capacity on the temperature indicated a critical crossover from the 3D-Ising to the mean-field for all the studied systems. It was found that the heat capacity does play an important role for describing the asymmetric criticality of coexistence curves by the complete scaling theory.