Improved Microarray-Based Decision Support with Graph Encoded Interactome Data

In the past, microarray studies have been criticized due to noise and the limited overlap between gene signatures. Prior biological knowledge should therefore be incorporated as side information in models based on gene expression data to improve the accuracy of diagnosis and prognosis in cancer. As prior knowledge, we investigated interaction and pathway information from the human interactome on different aspects of biological systems. By exploiting the properties of kernel methods, relations between genes with similar functions but active in alternative pathways could be incorporated in a support vector machine classifier based on spectral graph theory. Using 10 microarray data sets, we first reduced the number of data sources relevant for multiple cancer types and outcomes. Three sources on metabolic pathway information (KEGG), protein-protein interactions (OPHID) and miRNA-gene targeting (microRNA.org) outperformed the other sources with regard to the considered class of models. Both fixed and adaptive approaches were subsequently considered to combine the three corresponding classifiers. Averaging the predictions of these classifiers performed best and was significantly better than the model based on microarray data only. These results were confirmed on 6 validation microarray sets, with a significantly improved performance in 4 of them. Integrating interactome data thus improves classification of cancer outcome for the investigated microarray technologies and cancer types. Moreover, this strategy can be incorporated in any kernel method or non-linear version of a non-kernel method

Wustite as a new precursor of industrial ammonia synthesis catalysts

Contradictory results about the best oxidic precursor of Fe ammonia synthesis catalyst prompted the present comparative investigation on wustite- and magnetite-based catalysts. Many physical (density, porous texture, crystalline phases, reduction rate, metal surface, abrasion loss) and catalytic (kinetic constants, thermoresistancy) properties have been determined on both catalysts. The wustite-based catalyst proved to be much more active, especially at lower temperatures, approaching the performances of Ru/C catalyst, except at high conversion. Possible reasons for such a behavior of the wustite-based catalyst are discussed, suggesting that a reconsideration of the present consolidated knowledge on Fe ammonia synthesis catalyst might be convenien

Ni Catalysts Supported Over TiO2, SiO2 and ZrO2 for the Steam Reforming of Glycerol

Ni-based catalysts supported on TiO2, ZrO2 and SiO2 (in the form of mesoporous Santa Barbara Amorphous 15 (SBA-15) and amorphous dense nanoparticles), were employed in the steam reforming of glycerol. Each sample was prepared by liquid phase synthesis of the support followed by impregnation with the active phase and calcination at 8008C or by direct synthesis through flame pyrolysis. Many techniques have been used to assess the physical chemical properties of both the fresh and spent catalysts, such as atomic absorption, N2 adsorption/desorption, XRD, SEM, TEM, temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), Micro-Raman and FTIR spectroscopy. The samples showed different textural, structural and morphological properties,as well as different reducibility and thermal resistance depending on the preparation method and support. Some of these properties were tightly bound to catalyst performance, in terms of H2 productivity and stability towards coking and sintering. A key parameter was the metal\u2013support interaction, which strongly depended on the preparation procedure. In particular, the stronger the interaction, the more stable the metallic Ni clusters, which in turn lead to a higher catalytic activity and stability. Surface acidity was also taken into account, in which the nature of the acid sites was differentiated (silanols, titanols or Lewis acid sites). The characterisation of the spent catalysts also allowed us to interpret the deactivation process. The formation of multi-walled nanotubes was observed for every sample, though it was only in some cases that this led to severe deactivatio

Ni Catalysts Supported Over TiO2, SiO2 and ZrO2 for the Steam Reforming of Glycerol

A 72-year-old man was admitted with one blade of a huge pair of shears in his left thorax. His hemodynamics deteriorated due to life-threatening vascular lesions. An urgent thoracotomy revealed several injuries to the intercostal vessels and left apical inferior lung lobe. The blade tip was stuck in the posterior chest wall, 2 cm adjacent to the descending aorta. The blade was removed, the lung was sutured, and the patient made a good recovery

“Silica and zirconia supported catalysts for the low-temperature ethanol steam reforming"

Ethanol steam reforming has been investigated in the low temperature range, focusing not only on H2pro-ductivity, but also on catalyst stability, very critical parameters under such conditions. Different supports(SiO2and ZrO2), active phases (Ni, Co, Cu) and reaction temperature (300–500◦C) have been employed.Ni confirmed the best performing active phase to promote ethanol decomposition and reforming alreadyat low reaction temperature. However, stability towards coking remains a key problem. The supportplays a key role from this point of view. Indeed, the stabilization of the active phase in very dispersedform allowed to reach stable catalyst performance with time-on-stream. SiO2, thanks to no Lewis acidityand sufficiently strong metal–support interaction, demonstrated an interesting support for Ni under theselected operating condition

One-Pot Transformation of Citronellal to Menthol Over H-Beta Zeolite Supported Ni Catalyst: Effect of Catalyst Support Acidity and Ni Loading

Citronellal was converted to menthol in a one-pot approach using H-Beta zeolite-based Ni catalyst in a batch reactor at 80 °C, under 20 bar of total pressure. The effects of H-Beta acidity (H-Beta-25 with the molar ratio SiO2/Al2O3 = 25 and H-Beta-300 with SiO2/Al2O3 = 300) and Ni loading (5, 10 and 15 wt %) on the catalytic performance were investigated. Ni was impregnated on H-Beta support using the evaporation-impregnation method. The physico-chemical properties of the catalysts were characterized by XRD, SEM, TEM, ICP-OES, N2 physisorption, TPR, and pyridine adsorption–desorption FTIR techniques. Activity and selectivity of catalysts were strongly affected by the Brønsted and Lewis acid sites concentration and strength, Ni loading, its particle size and dispersion. A synergetic effect of appropriate acidity and suitable Ni loading in 15 wt.% Ni/H-Beta-25 catalyst led to the best performance giving 36% yield of menthols and 77% stereoselectivity to (±)-menthol isomer at 93% citronellal conversion. Moreover, the catalyst was successfully regenerated and reused giving similar activity, selectivity and stereoselectivity to the desired (±)-menthol isomer as the fresh one. Graphical Abstract: [Figure not available: see fulltext.

Ni/TiO2 for ethanol steam reforming: which is the best synthetic approach?

The performance of Ni/TiO2 catalysts in ethanol steam reforming (SR) was considered in this study; in particular, the effects of both the methodology of Ni introduction and calcination temperature were deeply investigated. Activity strongly depends on the physico-chemical properties of the catalyst, that greatly change according to the synthetic approach. Introduction Ethanol SR for a cleaner hydrogen production is an attracting topic for researchers and the design of a highly active and selective catalyst is a key point for the fulfilment of this process on industrial scale. Nickel is known to be both active and selective in the SR reactions, but also the support plays an essential role. The aim of this work is the investigation of the effect of the synthetic parameters on the physico-chemical properties of the sample and on its catalytic performance. Experimental TiO2 support was prepared by a conventional precipitation method . Ni (10 wt%) was added to the support by means of incipient wetness impregnation with an aqueous solution of the metallic precursor, either before (NiC) or after (CNi) the calcination of the support. Samples were calcined at 500 \ub0C (NiC500 and CNiC500) or at 800 \ub0C (NiC800). The samples were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR), high-resolution transmission electron microscopy (HR-TEM) and N2 physisorption. Activity tests were performed after reduction of the catalysts in H2 flow for 1h at 500 \ub0C for samples calcined at 500 \ub0C, at 800 \ub0C for NiC800. The activity tests were carried out at atmospheric pressure by feeding a 3:1 (mol/mol) H2O:CH3CH2OH mixture at 500 \ub0C. Results and discussion The characterization measurements we carried out reveal marked differences among the samples, in particular for what concerns the interactions between the active phase and the support and, as a consequence, Ni availability to the reaction. XRD pattern on NiC500 before the reduction reveals only nanocrystalline anatase. This suggests that all nickel species have been incorporated in the anatase lattice1, , thus making Ni unavailable for the reaction. In fact, this sample is almost completely inactive in ethanol SR. Ni incorporation in TiO2 is due to Ni impregnation before the calcination of the support. When Ni is added to the calcined support (CNiC500), no incorporation in the anatase lattice is detected. This sample is more active than NiC500 (EtOH conversion: 82%; H2 productivity: 0.21 mol min-1 kgcat-1), but it is not stable. The calcination treatment at high temperature (NiC800) stabilizes the active phase by strengthening the interactions of Ni species with the support (SMSI), with the formation of an ilmenite-type structure (NiTiO3) in which nickel is still reducible to Ni0. The catalytic performance of this catalyst is satisfactory, with an ethanol conversion of 99% and a H2 productivity of 0.84 mol min-1 kgcat-1. Conclusions The ability of the support to increase Ni availability to the reaction and to stabilize the active phase is of primary importance to achieve both high ethanol conversion and H2 productivity. The results indicate that TiO2-supported Ni systems are very sensitive to the synthetic procedure. The best catalytic performances are obtained by calcining at the highest temperature

“Ni/ZrO2 catalysts for ethanol steam reforming: effect of Ca-doping”

Ni/ZrO2 catalysts doped with various percentage of CaO were synthesized and used in the steam reforming of ethanol for hydrogen production. The addition of CaO to the support decreases the Lewis acidity of zirconia, which contributes to the side reactions that lead to coke deposition. Moreover, the replacement of the Zr4+ cation in the ZrO2 lattice with cations with lower positive charge, as Ca2+, generates oxygen vacancies which modify the interaction between the active phase and the support and activate CO2, thus favoring the gasification of coke. The sample doped with the maximum percentage of CaO presents an optimum carbon balance, which can enhance the catalyst durability