No abstract

No abstract

The MgO and P 2 O 5 -promoted c-Al 2 O 3 supports with alkaline and acidic natures, respectively, were prepared, impregnated with Mo atoms, and compared for dibenzothiophene (DBT) hydrodesulfurization (HDS) reaction. Ultraviolet spectroscopy and the principal component analysis were used to identify the impact of the supports on the reaction pathways. The catalysts were characterized by BET surface analysis, X-ray diffraction, temperature-programmed reduction, Fourier transform infrared, and X-ray photoelectron spectroscopy. The cAl 2 O 3 -supported catalyst favors the hydrogenation pathway relative to the MgO-supported catalyst, which facilitates the direct desulfurization route. The different performance was attributed to the dissimilar Mo phases that emerged during the activation procedure. The activation under sulfo-reductive condition changed the Mo atoms on c-Al 2 O 3 support into the sulfide phase while extra oxidation took place for the MgO-supported catalyst. The migration and consumption of loosely bonded bulk oxygen atoms with under-coordinated Mo atoms on the MgO support were introduced as a possible reason for such extra oxidation. DFT calculations predicted an interaction between the Mo/MgO catalyst and DBT via the electron donation from the catalyst oxygen atoms to the aromatic rings, resulting in weakening and breaking of the C-S bonds. In spite of the higher resistance of the MgO-supported catalyst toward coking and its superior activity, its lower hydrogenation capability suggested using a dualfunction catalyst. Accordingly, two catalysts were mixed and the synergism was observed in the HDS reaction of thiophene.

Chemotherapy is one of the main treatment regimens for cancer therapy. Efficacy of chemotherapy is limited issues such as nonspecific cytotoxicity, poor aqueous solubility, and bioavailability. Targeted drug delivery is an ideal strategy to overcome these barriers. Fe3O4 magnetic nanoparticles (MNPs) as a great drug delivery system have drawn considerable attention. Functionalized nanoparticles (NPs) here were synthesized by the coprecipitation method and characterized by thermogravimetric analysis and transmission electron microscopy techniques. An anticancer agent, doxorubicin (DOX), was loaded onto the NPs and then the release behavior and cytotoxicity effects of nanodrug were determined. The pH‐sensitive behavior of drug release was observed. While the total loaded drug was released at pH 1.2 in 30 min, the amount of drug release was equal to 8% in pH 7 after 8 h. The drug‐loading efficiency was found to be 88%. Also, NPs potentiate the efficacy of the drug by increasing its cytotoxicity, in which IC50 of 57 and 39 μM for the nanodrug and drug was estimated, respectively. In conclusion, the results of the study showed that MNPs are promising vehicle for DOX delivery.

No abstract