No abstract

Nanosized FeCo-based solids were prepared via distinct preparation procedures. The catalytic performances of the solids for styrene oxidation in the presence of hydrogen peroxide were evaluated. The addition of promoters in FeCo such as Sn, Mo, or Cu was also investigated. The catalysts were characterized with XRD, Raman spectroscopy, TEM, chemical analyses, EPR and SEM-EDS. Of these solids obtained via four different methods, the catalyst prepared via the NC and CM procedures enabled a partial incorporation of the Sn into the FeCo matrix forming a very active phase, namely the Heusler alloy. This was ascribed to the high initial dispersion of Sn as a promoter into the FeCo matrix, which led to available FeCoSn (FCS) particles well dispersed and stable on the catalyst surface. In the case of incorporating Mo or Cu to the nanosized FeCo catalyst, a poor stability towards leaching was observed when operating under the same reaction conditions. Cu was much less active than both Sn and Mo, mainly leading to acetophenone, ethylbenzene, 2-phenyl ethanol, 2-phenyl acetic acid, and 2-phenyl acetaldehyde products. The best catalytic results under the optimized reaction conditions, especially at 50 • C and styrene/H 2 O 2 molar ratio of 1 were achieved with nanosized FCS. This solid had a conversion of ca. 70% and selectivity for aldehydes of ca. 27%, and the selectivity for the condensation products was 29%.

Background Parkinson's disease (PD) is a neurodegenerative disease, which has an upward progression. In advanced stages, motor symptoms cause functional impairment to patients due to the degeneration of the substantia nigra. In early stages of PD, there is a sensory impairment, and patients report visual processing dysfunction. There is still no cure for PD, and early diagnosis is essential to slow disease progression. New method Given the good anatomical representation and organization of the visual system in the cerebral cortex, in this study, we propose a biomarker of PD using EEG signals, photic stimulation, partial directed coherence (PDC) to perform feature extraction, and machine learning (ML) techniques. Our goal is to classify participants into three distinct groups: PD patients who are medicated; patients with PD and drug deprivation; and healthy subjects. Results We were able to achieve outstanding results, above 99% of accuracy and kappa statistic up to 0.98 using random forests and feature selection techniques. Comparison with existing methods: Our approach was evaluated using several ML methods. As features, we initially used the electrodes, without explicitly extracting feature vectors over signal samples. Conclusions The good results we obtained by using random forests made possible clinical applications for the early detection of PD and, consequently, better prognosis and patient's quality of life.

No abstract

Oxides with good catalytic performances and more selectivity to valuable chemicals attract numerous research interests for the oxidation of hydrocarbon fuels. Taking advantage of the nanocasting route, CeFe-based nanocomposites were prepared and characterized to achieve superior stability in the oxidation of cyclic compounds. Adding a third metal (Me = Ni2+, Mn2+/Mn3+ or Co2+/Co3+) to the CeFe-based oxide helped the formation of Ce3+/Ce4+, Fe2+/Fe3+ and active couples in the ternary nanocomposites. The solids having a spherical morphology and good textural properties enabled the formation of promising ternary oxide catalysts for the oxidation of ethylbenzene compared with those of binary and single monoxide nanocomposites. The close contact among the Ce3+/Ce4+ and Fe2+/Fe3+ pairs with Ni2+ species provided the formation of a highly stable CeFeNi catalyst with enhanced performance in the oxidation of cyclic compounds such as ethylbenzene, styrene and benzyl alcohol substrates.

No abstract

No abstract

The Senna genus has a wide diversity of species, with an interesting chemical composition of secondary metabolites and applications as medicine. The folk medicine, mainly in developing countries, uses species of Senna to treat seizures, epilepsy, and constipation.Though the recognized bioactivity, some Brazilian native species of Senna remain unexplored, such as Senna cearensis, a native species of Caatinga. This is the first report about the bioactivity of the flowers of Senna cearensis Afr. Fern., a native species of northeast Brazil. In this communication, flavonoids and catechins are identified in Senna cearensis flowers and the chemical composition is linked with its antioxidant, anticholinesterase, and cytotoxic activities.By LC-MS, some compounds that belong to the class of flavonoids were identified. They are: catechin, epigallocatechin, guibourtinidol-(4α-8)-catechin, and cassiaflavan-(Cat)-epicatechin.The cytotoxic activity is more noticeable for the HL60 (leukemia) cell line with a cell growth inhibition (GI%) of 81.65 ± 5.65.