Particle size effect in methane activation over supported palladium nanoparticles

A synthesis method for producing MgAl oxide supported uniform palladium nanoparticles with varying diameters has been developed. The method consists of reductive-thermal decomposition of a PdMgAl hydrotalcite-like compound, formed via co-precipitation of metal nitrate salts and sodium carbonate. The hydrotalcite–like precursors were characterized by XRD, TG-MS and SEM, and were found to contain a well-defined crystalline structure and a uniform distribution of all constituent elements. The resulting catalysts were characterized by XRD, TEM, Chemisorption of CO and in situ IR measurements of CO, and were found to consist of partially oxide-embedded Pd nanoparticles with diameters ranging from d = 1.7 to 3.3 nm and correspond dispersions of 67–14%. Furthermore, the particle size was found to be inversely related to Pd loading. The palladium catalysts were studied for methane activation via chemisorption at 200 and 400 °C followed by a temperature programmed surface hydrogenation. The most disperse catalyst (d = 1.7 nm) possessed an intrinsic methane adsorption capacity, which was an order of magnitude larger than that of other catalysts in the series, indicating a strong structure sensitivity in this reaction. Additionally, the methane adsorption capacity of the hydrotalcite-derived Pd catalysts was nearly two orders of magnitude higher than that of catalysts derived through other synthesis pathways such as colloidal deposition or sonochemical reduction

Syngas Production Using Natural Gas from the Environmental Point of View

The search for clean and low-cost fuels as alternative for petroleum is a popular research focus in the energy field. The demand of natural gas as an energy source has increased steadily. The high H:C ratio and the absence of heteroatoms make natural gas an attractive feedstock for synthetic fuels and chemicals that can replace those that are typically petroleum-derived. The search for efficient routes to convert methane to other higher added-value products is a challenge for the scientific community. In addition, new fields of oil and gas contain associated CO2 (8–18%), and, in some specific fields, the associated gas encloses a higher CO2 content (79%). In this context, the tri-reforming process combines two of the most problematic greenhouse gases (CH4 and CO2) to generate syngas for the synthesis of clean liquid fuels and valuable chemicals. Developments in tri-reforming processes, which include the new catalysts, are presented in this chapter

Role of complement in in vitro and in vivo lung inflammatory reactions

Complement is one of the integral buttresses of the inflammatory response. In addition to host defense activities, proinflammatory properties of several complement components are described. This overview elucidates the role of complement in inflammatory reactions in vitro and in vivo, focusing on the complement activation products, C5a, and the membrane attack complex, C5b‐9. Using several approaches, the impact of these complement components in mechanisms relevant to neutrophil recruitment is emphasized. In addition, the participation of complement in endothelial superoxide generation and its essential requirement for full expression of lung injury is demonstrated, as are the involved intracellular signal transduction pathways. Understanding the mechanisms of complement‐induced proinflammatory effects may provide a basis for future therapeutic blockade of complement and/or its activation products. J. Leukoc. Biol. 64: 40–48; 1998.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142061/1/jlb0040.pd

Prospective Clinical Trial for Septic Arthritis:Cartilage Degradation and Inflammation Are Associated with Upregulation of Cartilage Metabolites

Background. Intra-articular infections can rapidly lead to osteoarthritic degradation. The aim of this clinical biomarker analysis was to investigate the influence of inflammation on cartilage destruction and metabolism. Methods. Patients with acute joint infections were enrolled in a prospective clinical trial and the cytokine composition of effusions (n=76) was analyzed. Characteristics of epidemiology and disease severity were correlated with levels of cytokines with known roles in cartilage turnover and degradation. Results. Higher synovial IL-1β concentrations were associated with clinical parameters indicating a higher disease severity (p<0.03) excluding the incidence of sepsis. Additionally, intra-articular IL-1β levels correlated with inflammatory serum parameters as leucocyte counts (LC) and C-reactive protein concentrations (p<0.05) but not with age or comorbidity. Both higher LC and synovial IL-1β levels were associated with increased intra-articular collagen type II cleavage products (C2C) indicating cartilage degradation. Joints with preinfectious lesions had higher C2C levels. Intra-articular inflammation led to increased concentrations of typical cartilage metabolites as bFGF, BMP-2, and BMP-7. Infections with Staphylococcus species induced higher IL-1β expression but less cartilage destruction than other bacteria. Conclusion. Articular infections have bacteria-specific implications on cartilage metabolism. Collagen type II cleavage products reliably mark destruction, which is associated with upregulation of typical cartilage turnover cytokines. This trial is registered with DRKS00003536, MISSinG

Phagocytes and the Lung

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72927/1/j.1749-6632.1997.tb46258.x.pd

Histone Variant H2A.J Is Enriched in Luminal Epithelial Gland Cells

H2A.J is a poorly studied mammalian-specific variant of histone H2A. We used immuno histochemistry to study its localization in various human and mouse tissues. H2A.J showed cell-type specific expression with a striking enrichment in luminal epithelial cells of multiple glands including those of breast, prostate, pancreas, thyroid, stomach, and salivary glands. H2A.J was also highly ex pressed in many carcinoma cell lines and in particular, those derived from luminal breast and prostate cancer. H2A.J thus appears to be a novel marker for luminal epithelial cancers. Knocking-out the H2AFJ gene in T47D luminal breast cancer cells reduced the expression of several estrogen-responsive genes which may explain its putative tumorigenic role in luminal-B breast cancer

Los sistemas de informacion en la Municipalidad de Talca : diagnostico y propuesta

145 p.La presente investigación tiene como objetivo analizar los Sistemas de Información computacionales de la Ilustre Municipalidad de Talca, detectar posibles problemas en estos y darles una solución que permita la aplicación de Tecnologías de Información que se encuentren presentes en el mercado. En Ios casos que no sea posible aplicar dichas Tecnologías de Información se propondrán soluciones alternativas de carácter administrativo. Este trabajo intenta visualizar al funcionamiento municipal y a su grado de actualización y adaptación a Ios cambios que se producen en el medio ambiente y que afectan el servicio que esta organización le brinda a la ciudadanía. La gran cantidad de cambios que se producen en el ámbito informático y que se expresan a través de nuevas Tecnologías de Información hace necesario preguntarse como están absorbiendo estos cambios los Sistemas de Información que posee la Ilustre Municipalidad. Si existe un manejo eficiente de la información dentro de la Ilustre Municipalidad, el servicio que esta entrega será también mas eficiente y será percibido como de mayor calidad por parte de la ciudadanía. Con respecto a las soluciones que se plantean al final de esta investigación se hace necesario señalar que si son implementadas debe ser considerando que Ios cambios generalmente son resistidos por quienes se ven afectados y no hay por que pensar que esta será la excepción, por lo que es imprescindible preparar a los funcionarios para la introducción de nuevas tecnologías