The role of carbon deposition on precious metal catalyst activity during dry reforming of biogas

Gold and palladium were supported on a mesoporous TiO₂ for total oxidation of volatile organic compounds (VOCs). Mesoporous high surface area titania support was synthesised using of Ti(OC₂H₅)₂ in the presence of CTMABr surfactant. After removing the surfactant molecules, 0.5 or 1.5 wt% of palladium and 1 wt% of gold were precipitated on the support by, respectively, wet impregnation and deposition–precipitation methods. The activity for toluene and propene total oxidation of the prereduced samples follows the same order: 0.5%Pd-1%Au/TiO₂ > 1.5%Pd/TiO₂ > 0.5%Pd/TiO₂ > 1%Au-0.5%Pd/TiO₂ > 1%Au/TiO₂ > TiO₂. Moreover, a catalytic comparison with samples based on a conventional TiO₂, shows the catalytic advantage of the mesoporous TiO₂ support. The promotional effect of gold added to palladium could be partly explained by small metallic particles (TEM), but meanly by metallic particles made up of Au-rich core with a Pd-rich shell. Moreover, the hydrogen TPR profile of 0.5%Pd-1%Au/TiO₂ shows only the signal attributed to small PdO particles. Gold also implies a protecting effect of the support under reduction atmosphere. Operando diffuse reflectance infrared fourier transform (DRIFT) spectroscopy was carried on and allowed to follow the VOCs oxidation and the formation of coke molecules, but also a metallic electrodonor effect to the adsorbed molecule which increases in the same order as the activity for oxidation reaction. The presence of coke after test was also shown by DTA–TGA by exothermic signals between 300 and 500 °C and by EPR (g = 2.003).     

Characterization and screening for mutations of the growth arrest-specific 11 (GAS11) and C16orf3 genes at 16q24.3 in breast cancer

BACKGROUND: Both fibroblast-mediated cytokine gene therapy and bone marrow transplantation (BMT) have proven to be efficient protocols for the recovery of bone marrow depression. In this report, the effects of fibroblast-mediated interleukin (IL)-6 gene therapy, in combination with BMT, on the recovery of irradiation-induced bone marrow depression were investigated. METHODS: NIH3T3 fibroblast cells engineered to secrete IL-6 (NIH3T3-IL-6) or NIH3T3 cells transduced with the neomycin gene (NIH3T3-Neo), in combination with 10(7), 10(6), or 10(5) syngeneic bone marrow cells, were implanted into irradiated mice. RESULTS: The platelets and white blood cells in the peripheral blood of the irradiated mice increased greatly 12 days after implantation of NIH3T3-IL-6 cells and BMT, the white blood cell counts were restored to a normal level 32 days after the combined therapy, and the platelet number was obviously higher than that in mice implanted with NIH3T3-Neo and BMT. Twenty and 25 days after the combined therapy, the mice showed accelerated recovery of colony-forming unit (CFU)-granulocyte/macrophages and CFU-megakaryocytes when compared with the mice implanted with NIH3T3-Neo cells and BMT. Ten days after lethal irradiation with gamma rays, the spleens formed more CFU-spleen in mice implanted with NIH3T3-IL-6 cells and BMT than in mice injected with phosphate-buffered saline or NIH3T3-Neo cells. Combined therapy with NIH3T3-IL-6 cell implantation and BMT delayed the survival period of the hematopoietic-depressed mice significantly when compared with therapy with NIH3T3-Neo cell implantation and BMT. CONCLUSIONS: These data demonstrated that the combined therapy of fibroblast-mediated IL-6 gene therapy and BMT could significantly promote the recovery of irradiation-induced hematopoietic depression.     

Impure anisotropic superconductors with variable density of states peaked away from the Fermi energy

A generalized BCS-type theory of impure superconductors with an anisotropic electron-electron interaction and variable electronic density of states is extended to the case in which the Fermi energy ε_F falls at an arbitrary position within the peak. It is found that when ε_F is well away from the center of the peak, then the reduction in the transition temperature due to the washing out of the anisotropy can in some cases be distinguished from that due to the density of states.     

PASting together the mammalian clock

Over the past year, the first components of the mammalian clock have been identified; Clock, bmal1 and three homologs of Drosophila period have been cloned, all of which encode PAS proteins. Expression of the mammalian period gene oscillates in many tissues in vivo and in immortalized cell cultures in vitro. Now, can we say that every cell has a circadian clock?     

Mass spectrometric study of the thermodynamic properties of solid Au−Pt alloys

The ratios of vapor pressures of gold in equilibrium with liquid gold and with each of eleven Au−Pt alloys have been measured over the approximate temperature range of 1340° to 1520°K by means of a dual-chamber effusion cell and a mass-spectrometric detection system. From these ratios, thermodynamic activities and related integral and partial molar thermodynamic quantities have been evaluated at 1423°K. When the thermodynamic quantities are referred to a hypothetical standard state of superheated gold at 1423°K, the results indicate both substantial positive deviations from ideal behavior and positive molar heats of mixing as is expected for miscibility-gap systems. The integral moalr quantities are adequately predicted by either the subregular or the Lumsden model. Observed integral entropies are discussed in terms of thermal, electronic, and configurational contributions, whereas the positive integral molar free energies are tentatively attributed to strain effects arising from ion-core repulsions. R. W. Jones formerly Graduate Student, Northwestern University, Evanston, Ill. This research was supported by the Advanced Research Projects Agency through the Northwestern University Materials Research Center. Partial support for the mass spectrometer facility was provided by the U. S. Atomic Energy Commission, Document Code COO-1147-30.     

Factor analysis of the Test Anxiety Scale and evidence concerning the components of test anxiety.

The scores of 1,200 undergraduates on Sarason's Test Anxiety Scale were factor analyzed. The analysis involved rotation to an orthogonal structure that produced 2 factors that accounted, respectively, for 53.45% and 31.50% of the total variance. Both cognitive "worry" and "emotionality" items loaded strongly on the 1st factor, which appears to reflect worry about oneself and one's performance on tests and a variety of physical and emotional consequences of this intense worry. The 2nd factor seems to reflect emotional distress in testing situations, but no worry or interference with performance, in persons who appear to lack a strong achievement orientation. Subscales based on these 2 factors were negatively correlated. Implications for the 2-component theory of test anxiety are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interfacial conduction in lithium iodide containing inert oxides

Temperature-dependent conductivities are reported for a lithium iodide sample sandwiched between two fused silica plates and for an LiI film deposited on a silica plate. The existence of an LiISiO₂ interfacial conduction path possessing a conductivity of about 5 ohm^?1 cm^?1 at 25 °C is confirmed. In addition, an infiltration technique for the preparation of LiI-ceramic particle composites is discussed.