High-temperature catalyst supports and ceramic membranes: Metastability and particle packing

Parameters and/or processes responsible for the stability of catalyst supports and ceramic membranes are discussed. Two major parameters/processes were identified which are responsible for the stability of sol-gel derived nanostructured oxides at elevated temperatures. They are metastable-to-stable phase transformation and structure and packing of primary particles within the aggregate. Based on these observations, strategies to develop thermostable nanostructured oxides for high-temperature membrane and catalyst applications are discussed by taking titania and titania-alumina nanocomposites as examples

Cal Poly Nano Hydro

This projects goal was to design, construct, and test a machine capable of generating a usable amount of energy from naturally flowing water. The device conceived for this purpose is a portable raft with a turbine mounted to the underside. The turbine is mated directly to a low angular velocity generator which outputs to a power electronics system on shore. Using a Gorlov Helical turbine, this proof-of-concept is designed to output ~50 Watts of electricity to charge a battery for later use. Possible applications for this device include camping in remote locations, supplemental power generation for a home, or for powering off-the-grid locations in developing countries

Difference in radiocarbon ages of carbonized material from the inner and outer surfaces of pottery from a wetland archaeological site

AMS (Accelerator Mass Spectrometry) radiocarbon dates for eight potsherds from a single piece of pottery from a wetland archaeological site indicated that charred material from the inner pottery surfaces (5052 ± 12 BP; N = 5) is about 90 14C years older than that from the outer surfaces (4961 ± 22 BP; N = 7). We considered three possible causes of this difference: the old wood effect, reservoir effects, and diagenesis. We concluded that differences in the radiocarbon ages between materials from the inner and outer surfaces of the same pot were caused either by the freshwater reservoir effect or by diagenesis. Moreover, we found that the radiocarbon ages of carbonized material on outer surfaces (soot) of pottery from other wetland archaeological sites were the same as the ages of material on inner surfaces (charred food) of the same pot within error, suggesting absence of freshwater reservoir effect or diagenesis

Atomic matter wave scanner

We report on the experimental realization of an atom optical device, that allows scanning of an atomic beam. We used a time-modulated evanescent wave field above a glass surface to diffract a continuous beam of metastable Neon atoms at grazing incidence. The diffraction angles and efficiencies were controlled by the frequency and form of modulation, respectively. With an optimized shape, obtained from a numerical simulation, we were able to transfer more than 50% of the atoms into the first order beam, which we were able to move over a range of 8 mrad.Comment: 4 pages, 4 figure

Self-similar shear-thickening behavior in CTAB/NaSal surfactant solutions

The effect of salt concentration Cs on the critical shear rate required for the onset of shear thickening and apparent relaxation time of the shear-thickened phase, has been investigated systematically for dilute CTAB/NaSal solutions. Experimental data suggest a self-similar behavior of the critical shear rate and relaxation time as functions of Cs. Specifically, the former ~ Cs^(-6) whereas the latter ~ Cs^(6) such that an effective Weissenberg number for the onset of the shear thickened phase is only weakly dependent on Cs. A procedure has been developed to collapse the apparent shear viscosity versus shear rate data obtained for various values of Cs into a single master curve. The effect of Cs on the elastic modulus and mesh size of the shear-induced gel phase for different surfactant concentrations is discussed. Experiments performed using different flow cells (Couette and cone-and-plate) show that the critical shear rate, relaxation time and the maximum viscosity attained are geometry-independent. The elastic modulus of the gel phase inferred indirectly by employing simplified hydrodynamic instability analysis of a sheared gel-fluid interface is in qualitative agreement with that predicted for an entangled phase of living polymers. A qualitative mechanism that combines the effect of Cs on average micelle length and Debye parameter with shear-induced configurational changes of rod-like micelles is proposed to rationalize the self-similarity of SIS formation.Comment: 27 pages, 17 figure

A double parton scattering background to Higgs boson production at the LHC

The experimental capability of recognizing the presence of b quarks in complex hadronic final states has addressed the attention towards final states with b\bar{b} pairs for observing the production of the Higgs boson at the LHC, in the intermediate Higgs mass range.We point out that double parton scattering processes are going to represent a sizeable background to the process.Comment: 9 pages, 2 figure

Nephrin and podocin dissociate at the onset of proteinuria in experimental membranous nephropathy

Nephrin and podocin dissociate at the onset of proteinuria in experimental membranous nephropathy.BackgroundThe slit diaphragm plays a critical role in maintaining the barrier function of the glomerular capillary wall. The pathogenic mechanism of proteinuria in membranous nephropathy remains uncertain. This study was undertaken to analyze the pathogenic role of slit diaphragm in proteinuria in experimental membranous nephropathy.MethodsThe expression and the localization of slit diaphragm–associated molecules (nephrin, podocin, and CD2AP) and other podocyte-associated molecules (podocalyxin and α3 integrin) in passive and active Heymann nephritis were analyzed by immunofluorescence and Western blot analysis. The interaction of slit diaphragm–associated molecules was investigated by the dual-labeling immunofluorescence method. The mRNA expression of these molecules was also analyzed.ResultsShifts in nephrin and podocin staining patterns, from linear to granular, were detected in the early stages of passive Heymann nephritis. These shifts were not parallel, and the dissociation of these molecules was detected by the dual-labeling immunofluorescence method in passive and active Heymann nephritis. Western blot analyses with sequentially solubilized materials indicated that the nephrin-rich fraction changed from being partly detergent-resistant to being predominantly detergent-soluble. This change did not occur with podocin. Nephrin excreted into urine was already detected in the early stages of passive Heymann nephritis. Decreased mRNA expression of nephrin and podocin was observed before the onset of proteinuria. By contrast, no extensive change in the expression of α3 integrin was observed in this study.ConclusionNephrin is dissociated from podocin and excreted into urine in the early stages of Heymann nephritis. The reduced expression of nephrin and podocin, along with their dissociation, may contribute to the development of proteinuria in Heymann nephritis

Resistin-Like Molecule-β Inhibits SGLT-1 Activity and Enhances GLUT2-Dependent Jejunal Glucose Transport

International audienceOBJECTIVE: An increased expression of RELM-beta (resistin-like molecule-beta), a gut-derived hormone, is observed in animal models of insulin resistance/obesity and intestinal inflammation. Intestinal sugar absorption is modulated by dietary environment and hormones/cytokines. The aim of this study was to investigate the effect of RELM-beta on intestinal glucose absorption. RESEARCH DESIGN AND METHODS: Oral glucose tolerance test was performed in mice and rats in the presence and the absence of RELM-beta. The RELM-beta action on glucose transport in rat jejunal sacs, everted rings, and mucosal strips was explored as well as downstream kinases modulating SGLT-1 and GLUT2 glucose transporters. RESULTS: Oral glucose tolerance test carried out in rodents showed that oral administration of RELM-beta increased glycemia. Studies in rat jejunal tissue indicated that mucosal RELM-beta promoted absorption of glucose from the gut lumen. RELM-beta had no effect on paracellular mannitol transport, suggesting a transporter-mediated transcellular mechanism. In studies with jejunal mucosa mounted in Ussing chamber, luminal RELM-beta inhibited SGLT-1 activity in line with a diminished SGLT-1 abundance in brush border membranes (BBMs). Further, the potentiating effect of RELM-beta on jejunal glucose uptake was associated with an increased abundance of GLUT2 at BBMs. The effects of RELM-beta were associated with an increased amount of protein kinase C betaII in BBMs and an increased phosphorylation of AMP-activated protein kinase (AMPK). CONCLUSIONS: The regulation of SGLT-1 and GLUT2 by RELM-beta expands the role of gut hormones in short-term AMPK/protein kinase C mediated control of energy balance

Molecular and functional heterogeneity of IL-10-producing CD4 + T cells

IL-10 is a prototypical anti-inflammatory cytokine, which is fundamental to the maintenance of immune homeostasis, especially in the intestine. There is an assumption that cells producing IL-10 have an immunoregulatory function. However, here we report that IL-10-producing CD4 + T cells are phenotypically and functionally heterogeneous. By combining single cell transcriptome and functional analyses, we identified a subpopulation of IL-10-producing Foxp3 neg CD4 + T cells that displays regulatory activity unlike other IL-10-producing CD4 + T cells, which are unexpectedly pro-inflammatory. The combinatorial expression of co-inhibitory receptors is sufficient to discriminate IL-10-producing CD4 + T cells with regulatory function from others and to identify them across different tissues and disease models in mice and humans. These regulatory IL-10-producing Foxp3 neg CD4 + T cells have a unique transcriptional program, which goes beyond the regulation of IL-10 expression. Finally, we found that patients with Inflammatory Bowel Disease demonstrate a deficiency in this specific regulatory T-cell subpopulation