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Physical exercise has many health benefits, including improved cardiovascular fitness, lean muscle development, increased metabolism, and weight loss, as well as positive effects on brain functioning and cognition. Recent evidence suggests that regular physical exercise may also affect the responsiveness of reward regions of the brain to food stimuli. We examined whether the total number of minutes of self-reported weekly physical exercise was related to the responsiveness of appetite and food reward-related brain regions to visual presentations of high-calorie and low-calorie food images during functional MRI. Second, we examined whether such responses would correlate with self-reported food preferences. While undergoing scanning, 37 healthy adults (22 men) viewed images of high-calorie and low-calorie foods and provided desirability ratings for each food image. The correlation between exercise minutes per week and brain responses to the primary condition contrast (high-calorie>low-calorie) was evaluated within the amygdala, insula, and medial orbitofrontal cortex, brain regions previously implicated in responses to food images. Higher levels of exercise were significantly correlated with lower responsiveness within the medial orbitofrontal cortex and left insula to high-calorie foods. Furthermore, activation of these regions was positively correlated with preference ratings for high-calorie foods, particularly those with a savory flavor. These findings suggest that physical exercise may be associated with reduced activation in food-responsive reward regions, which are in turn associated with reduced preferences for unhealthy high-calorie foods. Physical exercise may confer secondary health benefits beyond its primary effects on cardiovascular fitness and energy expenditure.

Au and Au-Ce promoted catalysts supported on zeolites (Beta, H-MCM-22, H-Mordenite, ZSM-5), mesoporous material MCM-41 and metal oxides (TiO2, SiO2, Al2O3) were prepared. Catalysts were characterized by a range of methods: nitrogen physisorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS), transmission electron microscopy (TEM) and activity was evaluated in selective aerobic piperonyl alcohol oxidation to piperonal. The effect of such catalyst ' s properties as Au particle size and Ce addition on the catalytic activity was highlighted.

Enantioselective hydrogenation of 1-phenyl-1,2-propanedione (PPD) over cinchona-modified oxide-supported platinum catalysts represents an extension to the well-known Orito reaction with methyl and ethyl pyruvates (EtPy) as typical substrates for the asymmetric reduction. In this paper, the adsorption of PPD and cinchonidine on a Pt catalyst was studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The catalyst preparation and the adsorption of the reactant and modifier were carried out according to the procedure generally used in catalysis under actual reaction conditions. The catalysts with adsorbed species were analyzed ex situ. The selective deposition of cinchonidine and PPD on the metal surface was confirmed by parallel experiments with alumina samples and by analyzing the platinum adsorption sites with carbon monoxide as a probe molecule. Among the IR visible adsorbed species, 1(O2)-configuration of PPD was found as the most populated on Pt surface under the conditions of ex situ measurements. New data on the mutual interactions among cinchonidine, PPD, and the Pt catalyst are presented. Tilted -bonded cinchonidine was detected on the surface under the modifier concentration profile used for obtaining high enantioselectivity in the hydrogenation of PPD. Hydrogen bonding between adsorbed cinchonidine and PPD was also detected.

Silica-gel-supported Pt–Cu alloy particles (diameter 4–8 nm) were prepared via sol–gel processing from mixtures of tetraethoxysilane, 3-(2-aminoethylamine)propyltriethoxysilane as anchors for metal ions, and acetates of Cu²⁺ and [Pt(NH₃)₄]²⁺ as metal sources. The calcined and reduced materials were characterized by transmission electron microscopy (carrier morphology and metal dispersion), photoelectron spectroscopy (global charge states) and diffuse reflectance infrared spectroscopy of chemisorbed CO to probe the electronic structure of the metal particles. The results obtained by the combined techniques provide evidence for the formation of supported Pt–Cu alloy particles, the detection of geometric and ligand effects, and an unusual redistribution of intensity between the bands corresponding to CO adsorbed on Cu and Pt atoms.

The electron-beam irradiation of Pd/Al2O3and Pd/C increased dispersion of Pd nanoparticles and activity in toluene hydrogenation by a factor of 3–4.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.