Catalytic chemical vapor deposition synthesis of single- and double-walled carbon nanotubes from α-(Al1−xFex)2O3 powders and self-supported foams

An investigation of the potential interest of α-alumina–hematite foams, as opposed to powders, as starting materials for the synthesis of carbon nanotubes (CNTs) by catalytic chemical vapor deposition method was performed. The oxide powders and foams as well as the corresponding CNT–Fe–Al2O3 composite powders and foams are studied by X-ray diffraction, specific surface area measurements, electron microscopy, Raman spectroscopy and Mössbauer spectroscopy. The latter technique revealed that four components (corresponding to α-Fe, Fe3C, γ-Fe-C and Fe3+) were present in the Mössbauer spectra of the composite powders, and that an additional sextet, possibly due to an Fe1−yCy alloy, is also present in the Mössbauer spectra of the composite foams. Contrary to some expectations, using foams do not lead to an easier reduction and thus to the formation of more α-Fe, Fe3C and/or γ-Fe–C potentially active particles for the formation of CNTs, and hence to no gain in the quantity of CNTs. However, using foams as starting materials strongly favors the selectivity of the method towards SWCNTs (60% SWCNTs and 40% DWCNTs) compared to what is obtained using powders (5% SWCNTs, 65% DWCNTs and 30% MWCNTs)

Electrical conductive double-walled carbon nanotubes � Silica glass nanocomposites prepared by the sol�gel process and spark plasma sintering

The electrical conductivity of suspensions in liquid of several kinds of carbon nanotubes (CNTs) is measured. Raw and soft-functionalized double-walled carbon nanotubes (DWCNTs) appear to be the most promising for achieving a low electrical percolation threshold. A 0.35 vol.% DWCNTs�SiO2 nanocomposite is prepared by the sol�gel process and densified by spark plasma sintering. The obtained material presents a fairly good dispersion of DWCNTs and its electrical conductivity (104 S cm1) is six orders of magnitude higher than that previously reported for 1 vol.% multi-walled CNTs�SiO2

Trust motivation: The self-regulatory processes underlying trust decisions

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this recordTheorizing about trust has focused predominantly on cognitive trust cues such as trustworthiness, portraying the trustor as a relatively passive observer reacting to the attributes of the other party. Using self-determination and control theories of motivation, we propose a model of trust motivation that explores the intraindividual processes involved in the volitional aspects of trust decision-making implied by the definition of trust as a willingness to be vulnerable. We distinguish between intrinsic and extrinsic drivers of trust and propose a two-phase model of trust goal setting and trust regulation. Our model offers a dynamic view of the trusting process and a framework for understanding how trust cognition, affect and behavior interact over time. Furthermore, we discuss how trust goals may be altered or abandoned via a feedback loop during the trust regulation process. We conclude with a discussion of potential implications for existing theory and future research

Eco-friendly Synthesis of Silver Nanoparticles and its Application in Hydrogen Photogeneration and Nanoplasmonic Biosensing

Environmentally friendly methods for silver nanoparticles (AgNPs) synthesis without the use of hazardous chemicals have recently drawn attention. In this work, AgNPs have been synthesized by microwave irradiation using only honey solutions or aqueous fresh pink radish extracts. The concentrations of honey, radish extract, AgNO3 and pH were varied. AgNPs presented mean sizes between 7.0 and 12.8 nm and were stable up to 120 days. The AgNPs were employed as co-catalyst (TiO2@AgNPs) to increase the hydrogen photogeneration under UV-vis and only visible light irradiation, when compared to pristine TiO2 NPs. The prepared photocatalyst also showed hydrogen generation under visible light. Additionally, AgNPs were used to assemble a nanoplasmonic biosensor for the biodetection of extremely low concentrations of streptavidin, owing to its specific binding to biotin. It is shown here that green AgNPs are versatile nanomaterials, thus being potential candidates for hydrogen photogeneration and biosensing applications

Borylation and rearrangement of alkynyloxiranes: a stereospecific route to substituted α-enynes

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OGR1 (GPR68) and TDAG8 (GPR65) Have Antagonistic Effects in Models of Colonic Inflammation

G-protein-coupled receptors (GPRs), including pro-inflammatory ovarian cancer GPR1 (OGR1/GPR68) and anti-inflammatory T cell death-associated gene 8 (TDAG8/GPR65), are involved in pH sensing and linked to inflammatory bowel disease (IBD). OGR1 and TDAG8 show opposite effects. To determine which effect is predominant or physiologically more relevant, we deleted both receptors in models of intestinal inflammation. Combined Ogr1 and Tdag8 deficiency was assessed in spontaneous and acute murine colitis models. Disease severity was assessed using clinical scores. Colon samples were analyzed using quantitative polymerase chain reaction (qPCR) and flow cytometry (FACS). In acute colitis, Ogr1-deficient mice showed significantly decreased clinical scores compared with wildtype (WT) mice, while Tdag8-deficient mice and double knockout (KO) mice presented similar scores to WT. In Il-10-spontaneous colitis, Ogr1-deficient mice presented significantly decreased, and Tdag8-deficient mice had increased inflammation. In the Il10$^{-/-}$ × Ogr1$^{-/-}$ × Tdag8$^{-/-}$ triple KO mice, inflammation was significantly decreased compared with Tdag8$^{-/-}$. Absence of Ogr1 reduced pro-inflammatory cytokines in Tdag8-deficient mice. Tdag8$^{-/-}$ had significantly more IFNγ$^{+}$ T-lymphocytes and IL-23 T-helper cells in the colon compared with WT. The absence of OGR1 significantly alleviates the intestinal damage mediated by the lack of functional TDAG8. Both OGR1 and TDAG8 represent potential new targets for therapeutic intervention

Catalytic chemical vapor deposition synthesis of double-walled and few-walled carbon nanotubes by using a MoO3-supported conditioning catalyst to control the formation of iron catalytic particles within an α-Al1.8Fe0.2O3 self-supported foam

α-Al1.8Fe0.2O3 and α-Al1.8Fe0.2O3-MoO3 self-supported foams are used as catalytic materials for the synthesis of carbon nanotubes by catalytic chemical vapor deposition. A MoO3-supported conditioning catalyst placed upstream in the reactor is more efficient than MoO3 present within the catalytic material in producing doublewalled and few-walled carbon nanotubes with fewer defects. It is shown that the corresponding modifications of the gas atmosphere (presence of H2O formed by the H2 reduction of MoO3 and, therefore, lower H2 and CH4 concentrations) allow one to limit more efficiently the release of the Fe catalyst from the oxide solidsolution foam, which results in the formation of fewer Fe nanoparticles, which, therefore, are less prone to undesirable growth. Thus, a MoO3-induced "solid-state" effect is demonstrated within the catalytic material without molybdenum species being themselves present within this material. This could lead to simplifications in the design of catalytic materials

Differential cargo mobilisation within Weibel-Palade bodies after transient fusion with the plasma membrane.

Inflammatory chemokines can be selectively released from Weibel-Palade bodies (WPBs) during kiss-and-run exocytosis. Such selectivity may arise from molecular size filtering by the fusion pore, however differential intra-WPB cargo re-mobilisation following fusion-induced structural changes within the WPB may also contribute to this process. To determine whether WPB cargo molecules are differentially re-mobilised, we applied FRAP to residual post-fusion WPB structures formed after transient exocytosis in which some or all of the fluorescent cargo was retained. Transient fusion resulted in WPB collapse from a rod to a spheroid shape accompanied by substantial swelling (>2 times by surface area) and membrane mixing between the WPB and plasma membranes. Post-fusion WPBs supported cumulative WPB exocytosis. To quantify diffusion inside rounded organelles we developed a method of FRAP analysis based on image moments. FRAP analysis showed that von Willebrand factor-EGFP (VWF-EGFP) and the VWF-propolypeptide-EGFP (Pro-EGFP) were immobile in post-fusion WPBs. Because Eotaxin-3-EGFP and ssEGFP (small soluble cargo proteins) were largely depleted from post-fusion WPBs, we studied these molecules in cells preincubated in the weak base NH4Cl which caused WPB alkalinisation and rounding similar to that produced by plasma membrane fusion. In these cells we found a dramatic increase in mobilities of Eotaxin-3-EGFP and ssEGFP that exceeded the resolution of our method (∼ 2.4 µm2/s mean). In contrast, the membrane mobilities of EGFP-CD63 and EGFP-Rab27A in post-fusion WPBs were unchanged, while P-selectin-EGFP acquired mobility. Our data suggest that selective re-mobilisation of chemokines during transient fusion contributes to selective chemokine secretion during transient WPB exocytosis. Selective secretion provides a mechanism to regulate intravascular inflammatory processes with reduced risk of thrombosis

Pandemic influenza vaccine & narcolepsy: Simulations on the potential impact of bias

Several studies have identified an association between PandemrixTM, an AS03 adjuvanted pandemic influenza A(H1N1) vaccine, and narcolepsy, a rare and under-diagnosed sleep disorder with a median onset-to-diagnosis interval of ten years. This paper reviews potential sources of bias in published studies and aims to provide, through simulation, methodological recommendations for assessment of vaccine safety signals. Our simulation study showed that in the absence of an association between the vaccine and the outcome, presence of detection bias and differential exposure misclassification could account for elevated risk estimates. These may play a major role, particularly in alert situations when observation times are limited and the disease has a long latency period. Estimates from the case-control design were less inflated than those from the cohort design when these biases were present. Overall, these simulations provide useful insights for the design and interpretation of future studies