329 research outputs found
Au-supported on Fe-doped ceria solids prepared in water-in-oil microemulsions: Catalysts for CO oxidation
Gold catalysts were synthesized by deposition-precipitation employing Fe-doped ceria systems, previously obtained by means of the water-in-oil microemulsions methodology with different iron contents (10, 25 and 50 Fe at.%). The final catalysts were tested in the CO oxidation reaction in presence of H2. After gold deposition the crystalline structure of the supports was not altered. Moreover no XRD lines associated to gold were detected, indicating its high dispersion. Solid solution was generated in all samples, although the segregation of iron oxide was detected for the material with the highest iron loading. This phenomenon was then enhanced for the corresponding gold catalyst that also presented sintering of the gold nanoparticles. Strong interaction between gold and the oxygen vacancies of the supports was demonstrated, as well as the promotion of the reducibility of surface Ce4+ and Fe3+ species at low temperatures. A remarkable promotion of the CO conversion at lower temperatures respect to that of the supports was observed for the gold catalysts. Below 120 °C, lower the amount of iron incorporated, higher the catalytic performance of the catalyst. This behaviour is closely related not only to a high gold dispersion but also to the ability for creating additional oxygen vacancies in the support, required for the CO oxidation reaction
Fischer–Tropsch Synthesis Over Zr-Promoted Co/γ-Al2O3 Catalysts
Two Zr-modified alumina supports were synthetized containing the same amount of Zr but a different distribution of this modifier over the alumina surface. These supports, together with the unmodified alumina carrier, were used to prepare three cobalt-based catalysts which were characterized and tested under relevant Fischer–Tropsch conditions. The three catalysts presented very similar porosity and cobalt dispersion. The addition of Zr nor its distribution enhanced the catalyst reducibility. The catalyst activity was superior when using a carrier consisting of large ZrO2 islands over the alumina surface. The use of a carrier with a homogeneous Zr distribution had however, a detrimental effect. Moreover, a faster initial deactivation rate was observed for the Zr-promoted catalysts, fact that may explain this contradictory effect of Zr on activity. Finally, the addition of Zr showed a clear enhancement of the selectivity to long chain hydrocarbons and ethylene, especially when Zr was well dispersed
Fe-doped ceria solids synthesized by the microemulsion method for CO oxidation reactions
A series of Ce-Fe mixed oxides as well as the pure oxides were synthesized by the microemulsions method. The solid solution formation was established for all the Fe-doped systems and only a hardly noticeable segregation of α-Fe2O3 was appreciated for the solid with the maximum iron content (50at.% Fe). The oxygen exchange is improved for all the Fe-doped systems; however the 10at.% Fe appears as the optimal iron content for achieving the maximum oxygen vacancies concentration and the higher reducibility efficiency. The CO oxidation (TOX, PROX) is especially achieved for the solids with the lower iron contents but with a superior oxygen vacancies proportion. These Ce-Fe systems prepared from microemulsions are very attractive to be considered as supports for depositing active phases capable of enhancing oxygen exchange ability of the whole system, allowing higher CO oxidation abilities.Ministerio de Ciencia e Innovación ENE2009-14522-C05-01Junta de Andalucía P09-TEP-545
Repair of a Reinforced Earth Wall
The facing of a Reinforced Earth retaining wall, built at an altitude of 1200 m, was damaged during the winter 1981. The repair was achieved quickly and under traffic. The instrumentation carried out on the repairs and the tests run on the backfill material have revealed the action of the frost and its increase in the fortuitous presence of water
(Not so) Great Expectations: Listening to Foreign-Accented Speech Reduces the Brain’s Anticipatory Processes
This study examines the effect of foreign-accented speech on the predictive ability of our brain. Listeners actively anticipate upcoming linguistic information in the speech signal so as to facilitate and reduce processing load. However, it is unclear whether or not listeners also do this when they are exposed to speech from non-native speakers. In the present study, we exposed native Dutch listeners to sentences produced d non-native speakers while measuring their brain activity using electroencephalography. We found that listeners’ brain activity differed depending on whether they listened to native or non- native speech. However, participants’ overall performance as measured by word recall rate was unaffected. We discussed the results in relation to previous findings as well as the automaticity of anticipation.Seventh Framework Programme (FP7)613465Theoretical and Experimental Linguistic
APC/CCdh1-Mediated Degradation of the F-Box Protein NIPA Is Regulated by Its Association with Skp1
NIPA (Nuclear Interaction Partner of Alk kinase) is an F-box like protein
that targets nuclear Cyclin B1 for degradation. Integrity and therefore activity
of the SCFNIPA E3 ligase is regulated by cell-cycle-dependent phosphorylation
of NIPA, restricting substrate ubiquitination to interphase. Here we show
that phosphorylated NIPA is degraded in late mitosis in an APC/CCdh1-dependent
manner. Binding of the unphosphorylated form of NIPA to Skp1 interferes with
binding to the APC/C-adaptor protein Cdh1 and therefore protects unphosphorylated
NIPA from degradation in interphase. Our data thus define a novel mode of
regulating APC/C-mediated ubiquitination
Facile Synthesis of Monodisperse CdS Nanocrystals via Microreaction
CdS-based nanocrystals (NCs) have attracted extensive interest due to their potential application as key luminescent materials for blue and white LEDs. In this research, the continuous synthesis of monodisperse CdS NCs was demonstrated utilizing a capillary microreactor. The enhanced heat and mass transfer in the microreactor was useful to reduce the reaction temperature and residence time to synthesize monodisperse CdS NCs. The superior stability of the microreactor and its continuous operation allowed the investigation of synthesis parameters with high efficiency. Reaction temperature was found to be a key parameter for balancing the reactivity of CdS precursors, while residence time was shown to be an important factor that governs the size and size distribution of the CdS NCs. Furthermore, variation of OA concentration was demonstrated to be a facile tuning mechanism for controlling the size of the CdS NCs. The variation of the volume percentage of OA from 10.5 to 51.2% and the variation of the residence time from 17 to 136 s facilitated the synthesis of monodisperse CdS NCs in the size range of 3.0–5.4 nm, and the NCs produced photoluminescent emissions in the range of 391–463 nm
A modular ligand-directed approach to label endogenous aminergic GPCRs in live cells
In the last two decades, new technologies based on luminescence have been developed to monitor the
organization, signalling or ligand binding of G Protein-Coupled Receptors. These technologies rely on the
overexpression of genetically modified (and/or fluorescently tagged) receptors of interest. However,
there is an increasing interest in developping approaches to conjugate chemical labels to specific residues
of native GPCRs, despite of the low reactivity and the high abundance of such residues.Peer reviewe
A modular click ligand-directed approach to label endogenous aminergic GPCRs in live cells
New technologies based on luminescence have been essential to monitor the organization, signaling, trafficking or ligand binding of G Protein-Coupled Receptors (GPCRs), but they rely on the overexpression of genetically modified receptors. As more and more studies indicate the importance of studying native receptors in their natural environment, it is essential to develop approaches allowing the specific labeling of native receptors. Here we report an innovative ligand directed approach to specifically label residues of native GPCRs upon ligand binding. To this end, we developed a ligand-directed toolbox based on a novel approach that uses molecular modules to build fluorescent ligand-directed probes that can label an archetypical aminergic GPCR (D1R). Our probes can be readily prepared before the labeling reaction from two molecular modules: an activated electrophilic linker which includes a fluorescent dye and a GPCR ligand that may include nucleophilic groups. Thanks to a fast and specific click reaction, the nucleophilic ligand can barely react with the activated linker before it is bound to the native target GPCR and the labeling reaction occurs. Subsequently, the ligand unbinds the GPCR pocket, leaving the receptor fluorescently labeled and fully functional. This novel labeling approach allowed us to label both D1 receptor in transfected cells and native receptors in neuronal cell lines. This approach will pave the way to develop new reagents and assays to monitor endogenous GPCRs distribution, trafficking, activity or binding properties in their native environment.Funding
Agence Nationale de la Recherche
ANR-17-CE11-0046
Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación and ERDF - A way of making Europe
CTQ2017-89222-R
Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación and ERDF - A way of making Europe
PCI2018-093047
Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación and ERDF - A way of making Europe
PID2020-120499RB-I00
Catalan government
2017 SGR 1604
the European Union's Horizon 2020 research and innovation program under Marie Skłodowska-Curie grant agreement No. 801342 (TecniospringINDUSTRY) and the Government of Catalonia's Agency for Business Competitive-ness (ACCIÓ).
TECSPR19-1-0062Peer reviewe
A modular ligand-directed approach to label endogenous aminergic GPCRs in live cells
Peer reviewe
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