849 research outputs found

    Editorial Catalysts: Supported Metal Catalysts and Their Applications in Fine Chemicals

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    Editorial to the Special" Issue Supported Metal Catalysts and Their Applications in Fine Chemicals

    Life cycle assessment of conventional and advanced two-stage energy-from-waste technologies for methane production

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    This study integrates the Life Cycle Assessment (LCA) of thermal and biological technologies for municipal solid waste management within the context of renewable resource use for methane production. Five different scenarios are analysed for the UK, the main focus being on advanced gasification-plasma technology for Bio Substitute natural gas (Bio-SNG) production, anaerobic digestion and incineration. Firstly, a waste management perspective has been taken and a functional unit of 1 kg of waste to be disposed was used; secondly, according to an energy production perspective a functional unit of 1 MJ of renewable methane produced was considered. The first perspective demonstrates that when the current energy mix is used in the analysis (i.e. strongly based on fossil resources), processes with higher electric efficiency determine lower global warming potential (GWP). However, as the electricity mix in the UK becomes less carbon intensive and the natural gas mix increases the carbon intensity, processes with higher Bio-SNG yield are shown to achieve a lower global warming impact within the next 20 years. When the perspective of energy production is taken, more efficient technologies for renewable methane production give a lower GWP for both current and future energy mix. All other LCA indicators are also analysed and the hot spot of the anaerobic digestion process is performed

    Therapeutic potential of targeting sphingosine kinases and sphingosine 1-phosphate in hematological malignancies

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    Sphingolipids, such as ceramide, sphingosine and sphingosine 1-phosphate (S1P) are bioactive molecules that have important functions in a variety of cellular processes, which include proliferation, survival, differentiation and cellular responses to stress. Sphingolipids have a major impact on the determination of cell fate by contributing to either cell survival or death. Although ceramide and sphingosine are usually considered to induce cell death, S1P promotes survival of cells. Sphingosine kinases (SPHKs) are the enzymes that catalyze the conversion of sphingosine to S1P. There are two isoforms, SPHK1 and SPHK2, which are encoded by different genes. SPHK1 has recently been implicated in contributing to cell transformation, tumor angiogenesis and metastatic spread, as well as cancer cell multidrug-resistance. More recent findings suggest that SPHK2 also has a role in cancer progression. This review is an overview of our understanding of the role of SPHKs and S1P in hematopoietic malignancies and provides information on the current status of SPHK inhibitors with respect to their therapeutic potential in the treatment of haematological cancers

    Effect of Carbon Support, Capping Agent Amount, and Pd NPs Size for Bio-Adipic Acid Production from Muconic Acid and Sodium Muconate

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    The effect of support, stabilizing agent, and Pd nanoparticles (NPs) size was studied for sodium muconate and t,t-muconic acid hydrogenation to bio-adipic acid. Three different activated carbons (AC) were used (Norit, KB, and G60) and carbon morphology did not affect the substrate conversion, but it greatly influenced the adipic acid yield. 1% Pd/KB Darco catalyst, which has the highest surface area and Pd surface exposure, and the smallest NPs size displayed the highest activity. Furthermore, the effect of the amount of the protective agent was studied varying metal/protective agent weight ratios in the range of 1/0.00-1/1.20, using KB as the chosen support. For sodium muconate reduction 1% Pd/KB_1.2 catalyst gave the best results in terms of activity (0.73 s-1), conversion, and adipic acid yield (94.8%), while for t,t-muconic acid hydrogenation the best activity result (0.85 s-1) was obtained with 1% Pd/KB_0.0 catalyst. Correlating the results obtained from XPS and TEM analyses with catalytic results, we found that the amount of PVA (polyvinyl alcohol) influences mean Pd NPs size, Pd(0)/Pd(II) ratio, and Pd surface exposure. Pd(0)/Pd(II) ratio and Pd NPs size affected adipic acid yield and activity during sodium muconate hydrogenation, respectively, while adipic acid yield was related by exposed Pd amount during t,t-muconic acid hydrogenation. The synthesized catalysts showed higher activity than commercial 5% Pd/AC
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