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In order to solve the adverse effects of sulfur oxides (SOx) released during the combustion process on the environment, health and economy, oxidative deep desulfurization of diesel has become a hotspot all over the world. In this paper, HY@TiO2-x composite catalysts with different TiO2 contents were synthesised by liquid-phase deposition using HY zeolite as the parent material. The catalysts were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet–Visible Diffuse Reflectance (UV–vis), Raman Spectroscopy, Scanning Electron Microscopy (SEM), N2-physisorption, X-ray Photoelectron Spectroscopy (XPS). The characterization results of XRD, FT-IR, UV–vis and Raman showed that TiO2 was successfully loaded on HY zeolite. The catalysts were applied to the oxidative desulfurization (ODS) and adsorption desulfurization of benzothiophene (BT) and dibenzothiophene (DBT). Under the selected reaction condition: T = 70℃, n(H2O2)/n(Sulfur) = 6, moil: mcatalyst = 35: 1. The results show that the HY@TiO2-1.5 catalyst has the best oxidation activity, and the conversion rates of BT and DBT were 85.0% and 99.7%, respectively. Meanwhile, the adsorption of BT and DBT were 5.06 and 10.93 mg-S/g-Cat. respectively. HY@TiO2-1.5 catalyst is simple to prepare, with a high activity of bulky organic sulfides adsorption-oxidative desulfurization and has a potential application in oil refining. The reasons for the improvement of organic sulfide adsorption and oxidative desulfurization activity on HY @ TiO2-1.5 catalyst are discussed. [ABSTRACT FROM AUTHOR]

The study of catalysts supported by polyoxometalates (POMs) with green oxidative desulfurization activity is an important research topic in oil refining. In this paper, a nano-sized H-β zeolite support was modified by tetraethyl orthosilicate (TEOS) and tetrabutyl titanate (TBOT) to form a microporous–mesoporous structure. On this basis, the modified H-β zeolite was used as a support to load POMs with different structures. The characterization results of Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, scanning electron microscopy (SEM), N2 adsorption–desorption, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy showed that POMs had been successfully loaded onto the support, and the skeleton structures of POMs and zeolites were maintained. The introduction of POMs significantly improved the ODS performance of bulky organic sulfides, especially benzothiophene (BT). The order of catalytic oxidative desulfurization activity of POMs with different structures was: Keggin > Sandwich ≈ Anderson > monovacant Dawson > Dawson > MoO3. Under the optimum reaction conditions: T = 50 °C, t = 1 h, moil : mcatalyst = 35 : 1, and n(O) : n(S) = 13 : 1, the oxidation conversion of BT and dibenzothiophene over the catalyst supported by phosphotungstic acid (HPW) reached 99.9%. The role of titanium active species, peroxide polyoxometalate, and titanium–silicon composite oxides in improving the oxidative removal of organic sulfides was discussed. [ABSTRACT FROM AUTHOR]

The n-octane hydroconversion catalysts were prepared by the impregnation of nanosized HZSM-5 with ammonium heptamolybdate or phosphomolybdic acid (PMA) precursors and were characterised by SEM, BET, FT-IR, UV–Vis, XRD, Py-IR and NH3-TPD. The hydroconversion of n-octane over a little phosphorus doping on the n-octane hydroconversion activity of MoO3/ZSM-5 catalysts has been investigated in order to obtain light isomers, alkanes and aromatic products with high octane number. In particular, the use of PMA increases the ability of aromatization and producing light iso-alkanes for nanosized HZSM-5 zeolites. The yield of total aromatics and i/n ratio over PMA-based MoO3/ZSM-5 catalysts reached 31.7 and 3.3 after 10 h of continuous reaction, respectively. When 0.2 wt% of phosphorus is added to the catalyst prepared from heptamolybdate, the activity is suppressed. A mixture of monoclinic β-MoO3 and orthorhombic α-MoO3 favors increasing aromatization performance over nanosized HZSM-5 zeolites, and orthorhombic α-MoO3 is beneficial to the production of light iso-alkanes. It could be attributed to the difference between orthorhombic α-MoO3 and monoclinic β-MoO3 as well as the structural dissimilarity between the two phases on nanosized HZSM-5 zeolites. The improved activity of n-octane hydroconversion over these catalysts and the mechanism of hydroconversion is discussed. [ABSTRACT FROM AUTHOR]

Riparian zones suffer from increased human disturbances and the plant communities change unpredictably in response to altered conditions. It is important to understand the effects of human activities on plant communities for rational tourism development and ecological protection programs. We sampled 14 and 27 sites in nearly natural and human-influenced landscapes along the Lijiang River in southwest China, respectively, to detect human impacts on the ecosystem. We set three survey lines, based on a submersion gradient, at each site to determine whether herbaceous species richness increased with distance from the river, and we examined the effects of disturbance on herbaceous distribution. The landscapes shared 101 common species, and unique species in the human-influenced landscape were partly synanthropic. The species richness and diversity indices of the nearly natural landscape were significantly higher than those of the human-influenced landscape (P < 0.01). Species richness increased with distance from the river in the nearly natural landscape, and a significant difference was detected among the variances of survey lines (P < 0.05) in the human-influenced landscape. In the nearly natural landscape, species richness increased with fewer hydrological effects, and a stable community was maintained. However, human disturbances led to community variability and fragmented riparian habitats, resulting in species extinction and ecological degradation. We suggest that appropriate dam and reservoir regulations, prohibition of soil destructions, and a long-term research program for ecosystem protection may help in improving the monitoring of human influences and sustainable management in riparian zones of tourist rivers.

Nanomaterials that are used in therapeutic applications need a high degree of uniformity and functionality which can be difficult to attain. One strategy for fabrication is to utilize the biological precision afforded by recombinant synthesis. Through protein engineering, we have produced ~27-nm dodecahedral protein nanoparticles using the thermostable E2 subunit of pyruvate dehydrogenase as a scaffold and added optical imaging, drug delivery, and tumor targeting capabilities. Cysteines in the internal cavity of the engineered caged protein scaffold (E2 variant D381C) were conjugated with maleimide-bearing Alexa Fluor 532 (AF532) and doxorubicin (DOX). The external surface was functionalized with polyethylene glycol (PEG) alone or with the tumor-targeting ligand folic acid (FA) through a PEG linker. The resulting bi-functional nanoparticles remained intact and correctly assembled. The uptake of FA-displaying nanoparticles (D381C-AF532-PEG-FA) by cells overexpressing the folate receptor was approximately six times greater than of non-targeting nanoparticles (D381C-AF532-PEG) and was confirmed to be FA-specific. Nanoparticles containing DOX were all cytotoxic in the low micromolar range. To our knowledge, this work is the first time that acid-labile drug release and folate receptor targeting have been simultaneously integrated onto recombinant protein nanoparticles, and it demonstrates the potential of using biofabrication strategies to generate functional nanomaterials.

ABSTRACT Background: Brucea javanica is an effective traditional medicine listed in Chinese Pharmacopoeia. In China, the seed oil of B. javanica has long been used as commercially available drug for [...]