Adsorption and coadsorption of CO and H on ruthenium surfaces

The interaction of CO with the Ru(0001) surface at several coverages (11.1, 25.0, and 33.3%) is studied, as well as the interaction of CO with a stepped Ru(0001) surface. The preference for the adsorption site (atop versus hcp) is analyzed with density of states diagrams. Hydrogen layers can be densely packed; 1 ML could, in fact, correspond to more than 100% coverage, where 100% coverage would correspond to one addatom for each metal atom on the surface. Calculations are made for 1 ML of adsorbed hydrogen up to 300% coverage for 2 x 2 supercells. The H coadsorption with CO (2 x 2 (CO + nH), n = 1, 3, 4) is discussed for different adsorption sites. The lateral interaction H-CO is repulsive. H-ads and COads prefer to form islands rather than mixed structures. CO is little influenced by coadsorption, except when 1 ML of atomic hydrogen is preadsorbed. H is strongly affected by coadsorption. The H adsorption sites become highly asymmetrical if H and CO share one metal atom

Preclinical considerations about affective disorders and pain: A broadly intertwined, yet often under-explored, relationship having major clinical implications

Background: Pain, a distinctive undesirable experience, encompasses several different and fluctuating presentations across varying mood disorders. Therefore, the present narrative review aimed to shed further light on the matter, accounting for both experimental animal models and clinical observations about major depressive disorder (MDD) pathology. Method: Major databases were inquired from inception until April 2016 for records about MDD and pain. Results: Pain and MDD are tightly associated with each other in a bi-directional fashion. Several cross-sectional and retrospective studies indicated a high presence of pain in the context of mood disorders, including MDD (up to 65%), but also increased prevalence rates in the case of mood disorders documented among people with a primary diagnosis of either psychological or somatic pain (prevalence rates exceeding 45%). The clinical implications of these observations suggest the need to account for mood and pain manifestations as a whole rather than distinct entities in order to deliver more effective interventions. Limitations: Narrative review, lack of systematic control groups (e.g., people with the primary diagnosis at review, but not the associated comorbidity as a study) to allow reliable comparisons. Prevalence rates and clinical features associated with pain varied across different studies as corresponding operational definitions did. Conclusions: Pain may have a detrimental effect on the course of mood disorders—the opposite holds. Promoting a timely recognition and management of such an often neglected comorbidity would therefore represent a primary goal toward the delivery of effective, multi-disciplinary care

Novel Ru-Mg-Al-O catalyst derived from hydrotalcite-like compound for NO storage/decomposition/reduction

Ru-Mg-Al hydrotalcite-like anionic clay (Mg/Al/Ru) 90: 29: 1) was successfully prepared with a constant-pH coprecipitation method. Calcination of a hydrotalcite-like precursor at 600 degrees C in the air gave rise to the well-mixed oxide Ru-Mg-Al-O that possesses a good dispersion of Ru species. Ru-Mg-Al-O catalyst after suitable pretreatment exhibits quite high NOx storage capability in the temperature range of 250-400 degrees C, and the highest NOx storage capability of about 220 mu mol g(-1) is obtained at 350 degrees C with flowing 790 ppm NO and 8% O-2 in N-2 stream. Meanwhile, the decomposition of 25-60% NO to N-2 as well as N2O is clearly observed on the catalyst at 300-400 degrees C. In situ diffuse reflectance Fourier transform ( DRIFT) spectra indicate that NOx is adsorbed and stored on a catalyst mainly in the form of various coordinated nitrites/ nitrates. On the basis of the NOx adsorption-desorption profiles as well as the in situ DRIFTS spectra, we have proposed a schematic outline for NOx storage and NO decomposition. Finally, the reduction of stored NOx species on the catalyst by H-2 was carried out at 350 degrees C, indicating that all adsorbed NOx species can be readily reduced by hydrogen