Search

A new method was developed to optimize the microwave heating thickness of the spent automobile catalyst in order to improve the uniform distribution of the temperature field. The average penetration depth and the microwave heating thickness of the spent automobile catalyst were calculated by Gauss model and numerical calculation based on dielectric loss tangent and reflection loss. The results showed that the spent automobile catalyst was a medium loss material. The average penetration depth was 1.11 m from room temperature to 800 °C. The optimum microwave heating thickness of the spent automobile catalyst was about 0.83 m or 0.75 times of the average penetration depth. Industrial application analysis indicated that the optimization of heating thickness could improve the uniform distribution of the temperature field and reduce energy consumption.

Self-labeled inhibitors (SLIs) are promising for creating links, ranging from cancer therapy and metastatic pathways to mechanistic elucidation. In this study, a new category of “two-in-one” fluorescent xanthone inhibitors was developed for the systematic evaluation of anticancer activity and the selective imaging of cytoplasm in vitro. These xanthone inhibitors presented high fluorescent brightness, working over a wide pH range enabled by a “switchable reaction” of the heterocyclic backbone. The strength and nature of fluorescence were probed via spectroscopic methods and density functional theory calculations on the molecular level, respectively. Along with the potent anticancer activity, which was demonstrated using MTT and clonogenic assays with high fluorescent brightness in the cytoplasm, SLI 3fd could be established as a modeled self-monitoring drug in cancer therapy.

Cavity perturbation method was used to determine the dielectric properties (ɛ′, ɛ″, and tan δ) of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption properties of zinc oxide dust and the feasibility of microwave roasting zinc oxide dust to remove fluorine and chlorine. The dielectric constant, dielectric loss, and loss tangent were proportional to the apparent density of zinc oxide dust. The effects of sample mass and microwave power on the temperature increase characteristics under the microwave field were also studied. The results show that the apparent heating rate of the zinc oxide dust increases with the increase in microwave roasting power and decreases with the increase in the sample mass. The temperature of the samples reaches approximately 800 °C after microwave treatment for 8 min, which indicates that the zinc oxide dust has strong microwave-absorption ability.

As a classical and well-established named reaction, the Nenitzescu reaction is of special value for the construction of biologically meaningful 5-hydroxyindole derivatives. However, to date, its sister, the anti-Nenitzescu reaction and the corresponding synthetic methodology for 3a-hydroxy-indol-6-one derivatives, has remained an unexplored area. We discovered herein an environmentally benign, mild, and catalyst-free reaction in ethanol for the site-selective construction of rarely fused [1,2-a]indolone derivatives (3) from quinones (1) and heterocyclic ketene aminals (HKAs) (2) via an unexpected anti-Nenitzescu strategy. This unconventional methodology suggests that it will be suitable for the site-selective synthesis of 3a-hydroxy-indol-6-one derivatives from a green perspective. On the other hand, the developed target compounds 3 have a promising future for the further synthesis of aromatic 6-hydroxyindoles or dehydroxylated indol-6-ones in situ. In order to systematically elucidate the mechanistic details and controlling factors of the two Nenitzescu reactions, density functional theory (DFT) calculations were also performed. According to the computational results, the origin of site-selectivity can be explained by the following reasons: all energy barriers for the anti-Nenitzescu reaction can be overcome at room temperature, yet the extremely high energy barrier of imine–enamine tautomerization for the Nenitzescu reaction indicates its failure under the same conditions. The reduced density gradient (RDG) analysis hinted that the greater thermodynamic stability of the Nenitzescu product 3h′ mainly depends on the release of the strong steric effect.

Zinc acetate and Zn-oxo complex of Zn4O(CH3COO)6 containing in the spent catalyst of vinyl synthesis were investigated by means of the first principles of density functional (DFT) methods. The geometries, energies, charge populations and local electron density distributions of the two compounds and their formate analogues were analyzed. Based on the pyrolysis characteristics of the spent catalyst, the thermodynamic properties of ΔG, ΔH and ΔS for possible decomposition reactions of zinc acetate and Zn4O(CH3COO)6 were calculated as functions of temperature. The results provide a theoretical evidence that Zn4O(CH3COO)6 is more stable than zinc acetate due to the regular Zn4O and ZnO4 tetrahedral coordination between Zn atoms and two kinds of O atoms. The preparation of Zn4O(CH3COO)6 via the hydrolysis of zinc acetate is thermodynamically feasible. Zn4O(CH3COO)6 is further decomposed into ZnO via a decarboxylation reaction rather than a hydrolysis reaction.

After being subjected to thermal treatment by microwave, a carbon-based spent catalyst from vinyl acetate synthesis has been proved to be a good precursor for the production of ZnO/activated carbon (AC) composites. Different operating activated times were found to have effect on the properties of the composites. As the activated time rises, the surface area of the activated carbon that is acting as the catalyst support increases due to the decomposition of the organic deposits that are clogging the porous structure. XRD was used to evaluate the transformation of zinc acetate to zinc oxide after thermal treatment. Both the iodine adsorption capacity and the yield of the resulting composites were calculated and SEM-EDX analysis was used to evaluate the changes in surface morphology.

ZnO/AC composite was prepared from spent catalyst of vinyl acetate synthesis by using conventional thermal treatment under CO2 atmosphere. The final composite was obtained with the operating conditions of activation temperature of 950°C, activation time of 120min and the CO2 flow rate of 600ml/min. The structure and surface properties of the ZnO/AC composite were observed and characterized by scanning electron microscope (SEM-EDX), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and the UV diffuse reflectance spectra. It was found that the zinc acetate present in the spent catalyst is transformed to zinc oxide (ZnO) after thermal treatment. ZnO particles were well adhered and uniformly distributed onto the carbon surface, forming ZnO/AC composite. The thermal treatment of the spent catalyst gives rise to a material with excellent adsorptive and photocatalytic properties.

It is proposed that human decidua contains a population of stem cells that are responsible for the proliferation ability during the process of embryo implantation and placenta formation and that factors in the crosstalk between the decidua and chorion may mediate decidual stem cell differentiation. This study analysed the phenotype of side population (SP) cells and investigated the clonogenicity and differentiation ability of SP cells in human decidua of early pregnancy. Serum-free culture-conditioned media of human decidua and chorion were obtained from decidua and chorion explant culture. Decidual SP cells were isolated by fluorescence-activated cell sorting. Different inducing media were added and the functional differentiation of decidual SP cells was examined. Decidual SP cells were negative for the mature decidual cell marker CD13 and prolactin and negative for CD34 and CD45 expression. Decidual SP cells formed clones after culture in colony-forming medium and they could form clones again. Differentiated cells expressing CD13 and prolactin were observed and stroma-like structures expressing CD13 were obtained. These results indicate that decidual SP cells are enriched for stem cell activity. Oestradiol, progesterone and factors in culture-conditioned media of human decidua and chorion induced their proliferation and differentiation.

A new technology for microwave pretreatment of spent catalyst on Zn extraction by HCl leaching was proposed and the temperature-change curve of spent catalyst under microwave irradiation was measured. The influence of microwave pretreatment temperature and microwave irradiation time on zinc extraction was investigated and the mechanism of microwave pretreatment for spent catalyst was analyzed. The results show that microwave pretreatment can greatly enhance the leaching rate of Zn. The Zn extraction reaches 96.58% under the conditions of microwave pretreatment temperature of 950 °C and the microwave irradiation time of 12 min. The blocked pores of spent catalyst can be opened through microwave pretreatment, increasing the contact area of leaching reagent and zinc.

The TG and DTG curves of self-made ZnO precursor were studied by the thermo-gravimetric analysis method in N2 atmosphere from 25°C to 650°C at the heating rate of 5, 10 and 15°C/min. The TG curve showed that the decomposition process started at about 150°C and finished at 300°C, in accordance with the temperature range of the decomposition from basic zinc carbonate to zinc oxide. The first level chemical reaction based on Coats-Redfern method was applied to estimate the activation energy of the decomposition. The correlation factor was about 0.99, and the calculated average activation energy was 33.89kJ/mol. Active zinc oxides were perpetrated by microwave heating at 350°C for 30min. Their composition and surface morphology were investigated by using scanning electron microscope and X-ray diffraction and its quality can reach the first-grade standard of HG/T2572-94.

An environmentally benign method for the selective preparation of fused indolone derivatives via anti-Nenitzescu strategy is developed.

To explore the existence of side-population cells (SP cells) in human decidual tissues in early pregnancy, and its biological characteristics.Decidual cells were obtained by enzymatic digestion from the decidual tissues of human early pregnancy. The cells then were stained with Hoechst33342 dye either alone or in combination with verapamil. Fluorescence-activated cell sorter (FACS) analysis was used to identify and isolate SP cells. The isolated cells were cultured in conditioned media culture to observe the proliferation and ability to form colony.Stem cells were found in the decidual tissues of early pregnancy with a percentage of 0.78% +/- 0.71% (0% - 3.20%). These cells further proliferated and formed colonies during long-time culture in vitro. No significant statistical difference was found in contents of SP cells among different gestational week (P0.05).SP cells exist in human decidua that can further proliferate and have the clonogenicity in culture in vitro.