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关键词： hollandites   sorption   photocatalysis   oxidation of CO and H-2   band gap  

摘要： Materials of the hollandite structure in the K2O-MeO(Me2O3)-TiO2 (Me = Al, Ni, Mg) system, synthesized by two methods (solid-phase synthesis and pyrolysis of citrate-nitrate compositions), were studied. The pyrolysis, compared to the traditional solid-phase synthesis, yielded the materials with the more developed specific surface and, as a consequence, enhanced performance in sorption of a model dye, Methylene Blue (for K2MgTi7O16, q = 18.75 mg g(-1)). The K2Al2Ti6O16 sample, also prepared by pyrolysis, showed the highest catalytic performance in oxidation of CO and H-2. The hydrogen oxidation on this catalyst occurred to 95% at 355 degrees C with the performance of similar to 0.21 x 10(-5)mol g(-1)s(-1), which is two times higher compared to the sample of the same composition prepared by the solid-phase method. The hollandites show promise as sorbents and catalysts for gas treatment.

关键词： Imidazolium based ionic liquids   Density   Viscosity   Speed of sound   Apparent molar volume   Jones-Dole equation  

摘要： This work presents the experimental data on thermophysical properties of aqueous solutions of imidazolium-based ionic liquids (ILs) such as 1-Ethyl-3-Methylimidazolium Ethylsulfate [EMIM][EtSO₄], 1-Ethyl-3-Methylimidazolium Methylsulfate [EMIM][MeSO₄], 1-Ethyl-3-Methylimidazolium Tosylate [EMIM][Tos], and 1,3-Dimethylimidazolium Methylsulfate [MMIM][MeSO₄] in water at different temperatures. Many researchers have studied imidazolium based ILs in different solvents but there is scarcity of data in dilute region. So the aim of this work is to understand the interactions between imidazolium based ILs and water in dilute region. To understand the ion-ion and ion-solvent interactions between IL and water, the thermophysical properties such as density (ρ), speed of sound (u), and viscosity (η) have been measured at temperatures T = (298.15, 303.15, 308.15 and 313.15) K and at atmospheric pressure. The properties like apparent molar volume, limiting apparent molar volume and coefficient of thermal expansion have been derived from the density data. The speeds of sound and density data were combined to evaluate isentropic and isothermal compressibilities. Using Jones-Dole equation, the viscosity A and B coefficients have been determined. The influence of IL cation chain length, different anions and temperature on the sign, magnitude of B_V (the deviation parameter from Debye-Hückel theory) and on viscosity B-coefficient has been discussed.

关键词： Adzuki bean   Dolichos bean   Starch   Structure   Properties  

摘要： The major carbohydrate in pulse is starch. The structure and physicochemical properties of starches from adzuki bean (AS) and dolichos bean (DS) were systematically compared in this work. Results showed that the differences in morphology (oval to kidney), crystal type (CA-type) and sugar linkage between AS and DS were minor. However, AS had lower amylose content (26.64%) and larger granule size than DS (31.85%). AS showed higher relative crystallinity, ratio of 1047/1022 cm(-1), single helix and double helix content (26.27, 0.95, 4.55 and 37.61%) than those of DS (24.08, 0.92, 4.76 and 27.49%, correspondingly), while AS may have loss of molecular order. Moreover, two kinds of anomalous linkages were detected by methylation analysis in AS and DS. These features contributed to higher swelling power, solubility, light transmittance and freeze-thaw stability of AS. Meanwhile, AS exhibited lower pasting and gelatinization temperatures, enthalpy and better pasting stability. The study indicated that amylose content, granular and crystalline structure of AS and DS may be responsible to their different properties. Hence, the study will improve the scientific basis on starches from adzuki bean and dolichos bean, and facilitate their utilization.

关键词： Artesunate   Cyclodextrin   Molecular modeling   Thermal analysis   FTIR   A375 cell line   HaCaT keratinocytes  

摘要： The use of cyclodextrins as carrier molecules is currently highly researched since they can improve not only the apparent water solubility and bioavailability of lipophilic drugs, but can also enhance stability or mask unpleasant tastes and smells. Artesunate is a naturally originated sesquiterpene derivative with great potential as an anticancer agent but poor water solubility. The aim of the present paper was the preparation, physicochemical characterization and biological activity assessment of three supramolecular adducts, namely guest-host inclusion complexes containing ATS as a guest molecule and randomly methylated-beta-cyclodextrin (CD1), heptakis (2,6-di-O-methyl)-beta-cyclodextrin (CD2) and heptakis (2,3,6-tri-O-methyl)-beta-cyclodextrin (CD3), each of them used separately as hosts. The pure precursors and prepared complexes were analyzed using FTIR spectroscopy and thermal analysis, the formation of the adducts was simulated using molecular modeling and the MTT in vitro proliferation method was employed in order to evaluate their cytotoxicity on healthy (HaCaT) and pathologic (A375) skin cell lines. The instrumental techniques proved the results obtained from the molecular simulation and confirmed the formation of all three inclusion complexes. The biological activity evaluation revealed a dose-dependent cytotoxicity of ATS on the cancer cell line, effect that was diminished after complexation, but also a significantly reduced toxic effect on the healthy cells for the complexes when compared to that determined by pure ATS.

关键词： apples   cider   fermentation   physicochemical composition   microorganisms  

摘要： Fermented apple beverages are produced all over the world with diverse characteristics associated with each country. Despite the diversifications, cider producers are confronted with similar issues and risks. The nature of the raw material, also known as the fermentation medium, plays a key role in fermentation. A well-defined composition of apples is, therefore, required to produce cider with good quality. In addition, ferment and its metabolism are important factors in the fermentation process. The producers of cider and other alcoholic beverages are looking in general for novel yeast strains or for the use of native strains to produce "authentic" and diversified beverages that are distinct from each other, and that attract more and more consumers. Research articles on cider production are infrequent compared to wine production, especially on the impact of the chemical composition and microbial diversity of apples on fermentation. Even though the processing of fermented beverages is close in terms of microbial interactions and production, the study of the specific properties of apples and the production challenges of cider production is advantageous and meaningful for cider producers. This review summarizes the current knowledge on apple composition and the impact of the must composition on fermentation and yeast growth. In addition, the microbial diversity of cider, activities, and its influence on fermentation are reviewed.

关键词： Cinnamon bark   Cinnamon twig   Fermented milk   Antioxidant activity   In vitro digestion  

摘要： This study was conducted to investigate the effect of cinnamon bark (CB) and twig (CT) extracts on the chemical (total phenolics (TPC), flavonoids (TFC), sugars content), physicochemical (pH, total acidity, shear viscosity) and antioxidant (DPPH, FRAP) properties of fermented milk (FM). Besides, the effect of in vitro digestion on the antioxidant activity of FM was also evaluated. Initially, the optimum extraction time of CB and CT were determined, followed by chemicals profiling by using UPLC-MS/MS. The encapsulated CB(ECB) and CT(ECT) were then prepared using maltodextrin. FMs (control, CB-/ECB-FM and CT-/ECT-FM) were prepared through fermentation using commercial starter cultures, and its physicochemical properties were ascertained. Lastly, the changes of chemical and antioxidant properties of FMs before and after digestion were determined. Results indicated that CB (from 1 h extraction) contained broader range of chemicals and exhibited higher antioxidant activity than CT (from 2h extraction). The chemical, physicochemical and antioxidant properties of FM were found significantly (p < 0.05) affected with the addition of CB and CT (both free and encapsulated form). Encapsulation successfully protected TFC from lost upon gastric digestion of ECB-FM, but not for ECT-FM. Nonetheless, antioxidant activity of all samples was dropped dramatically after intestinal digestion. Among the samples, only CB-FM exhibited the highest antioxidant activity (28.57 +/- 0.18% inhibition) upon digestion. This study provides an insight that post-digestive bioactivity should be used as the index to evaluate the bioactivity status of functional foods, instead of bioactivity level of the product itself.

关键词： Zeolite-zirconium   Fluoride adsorption   Pulsed sonication   Continuous sonication   Energy consumption  

摘要： The current work reports the first application of the fluoride removal using zeolite-zirconium powder in three modes of pulsed sonication, continuous sonication, and stirring. The properties of powdered zeolite-Zr were specified using surface analysis techniques (surface area: 109.71 m(2)/g and pore volume: 0.08 cm(3)/g). For all the studied modes, the highest removal rate was observed at pH 7, contact time of 80 min, and zeolite-Zr dose of 3 g/L. Adsorption-desorption experiments were carried out in 6 steps and the fluoride removal was reached to 80% for the final step. The effect of co-existing anions was also studied and chloride and nitrate did not have much effect on efficiency. The powdered zeolite-Zr demonstrated the high ability to remove fluoride from actual wastewater. The data of the present study were well suited to the model of the Freundlich isotherm and the pseudo-second-order kinetic. The pulsed sonication with a maximum adsorption capacity of 32.98 mg/g has been able to demonstrate better performance in comparison with the continuous sonication and stirring mode. (C) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

关键词： Chen'er gold deposit   fluid inclusion   gold mineralization   North China Craton   phase analysis  

摘要： The Chen'er gold deposit hosted in the Precambrian Taihua Supergroup metamorphic rocks is one of the typical gold deposits in the Xiaoqinling region along the southern margin of the North China Craton. The metallic mineral assemblage in this deposit includes sulfides, tellurides, native gold, electrum, and native bismuth. The telluride minerals are composed of calaverite, petzite, hessite, altaite, joseite;except for hessite and matildite, the other tellurides and native bismuth are first reported in this study. Fluid inclusion studies in the auriferous quartz reveal three types: aqueous, aqueous-carbonic, and carbonic inclusions. The homogenization temperatures range from 184 to 364 degrees C, and salinities are in the range of 1.74- to 11.47-wt.% NaCl equiv. At temperatures of 275 degrees C, the logfTe(2) and logfS(2) of the fluid are estimated as -16.13 to -8.19 and -12.74 to -4.80, respectively, and at temperatures of 305 degrees C, the pH and logfO(2) of the fluid are estimated as 3.61 to 5.69 and -34.31 to -27.81, respectively. It is inferred that Au(HS)(2)(-) and Au(HS)(0) are the predominant gold-bearing complexes, and tellurium was transported as Te-2(2-). Based on thermodynamic models of logfO(2)(g) versus pH, we suggest that the precipitations of native gold and electrum in the early and main mineralization stages are different, with the oxygen and hydrogen isotope values of auriferous quartz suggesting mixing of magmatic water with meteoric water.

关键词： The South China coast   Mangrove plants   Organic pollution   Shannon diversity index   Species richness index   Water temperature  

摘要： The phytoplankton diversity and community response to physicochemical variables in mangrove zones of Guangdong Province along the South China coast was investigated from October to December, 2017. This study was set to investigate the phytoplankton community structure in the mangrove zone and assess the relationship between the physicochemical variables and phytoplankton species diversity. Physicochemical variables such as water temperature, total dissolve solids (tds), pH, salinity, turbidity, electrical conductivity (EC) and nutrient salts were measured in situ across the 27 stations. A total of 451 species of phytoplankton were identified belonging to 10 groups (Bacillariophta > Cyanophyta > Chlorophyta > Euglenophyta > Dinoflagellate > Eubacteria > Ochrophyta > Crytophyta > Rhodophyta > Charophyta) and quantified to constitute a standing crop of 7.11 x 10(8) cells dm(-3). The principal component analysis (PCA) reveals that reactive nitrate, phosphate, electrical conductive (EC) and turbidity were the best abiotic factors that controlled the phytoplankton community structure in the area. However, Cannon Corresponding Analysis and Pearson correlation have explicitly revealed the impact of reactive nitrate, phosphate, EC and turbidity on the phytoplankton community structure. For instance, the CCA ordination revealed that species richness and evenness were positively influenced by reactive nitrate but negatively affected by EC, turbidity and water temperature. Diatoms were mostly controlled by total dissolved solids (tds) and salinity, whereas Euglena, cyanobacteria and green algae were impacted EC and turbidity, apart from the general contribution of the nutrient salts as delineated by CCA ordination. The Shannon diversity index value exposed different levels of organic pollution across the mangrove zone of which GD37 was the most impacted station.

关键词： Fluorous chemistry   Fluorous 1,2,3-triazoles   Sugar triazoles   Polyfluoroalkyl helicity   Physicochemical properties  

摘要： This paper describes a novel study of thirty closely related polyfluoroalkyl-substituted glycosidyl-1,2,3-triazoles with systematic variations in the type of sugar, D-glucos-1'-yl or D-galactos-6'-yl derivatives, the protected or unprotected form of the sugar, the length and nature of linker groups to the triazole, the point of attachment and the atom of attachment between the substituent and the triazole, and the length of the perfluoroalkyl chain. It reports for the first time the molecular structure and crystal structures of three of the candidates, as defined by single crystal X-ray diffraction analysis, and compares melting point and specific optical rotation values, in combination with the diffraction, NMR spectroscopic and computational data to establish structural features, such as the helical twist of the fluoroalkyl chains, that influence physicochemical properties in the solid and solution states. The results provide a valuable reference source for practitioners in the field and will aid in the design of future materials.