In Situ Development of a 3D Cu-CeO2 Catalyst Selective in the Electrocatalytic Hydrogenation of Biomass Furanic Compounds

The renewable electricity-driven electrocatalytic hydrogenation of biomass-derived furanic compounds produces biopolymer (polyurethane) precursors under mild reaction conditions. The widely used Ag and Cu electrocatalysts failed in the selective conversion of the aldehyde into the alcohol in concentrated electrolytes due to the contribution of the electrodimerization. Herein, we proposed 3D CeO2-based catalysts for the electrocatalytic hydrogenation of 5-hydroxymethylfurfural (HMF) electrolytes (0.02, 0.05, and 0.10 M) to 2,5-bishydroxymethylfuran (BHMF). An electrodeposition approach was adopted to coat CeO2 on Cu open-cell foams. The ex-situ characterization of electrocatalysts revealed that they were made of a CeO2 layer containing Cu species. The migration of Cu from the foam to the coating started during the electrodeposition, while the electroreduction conditions provoked the formation of Cu particles. The in situ characterization by X-ray absorption spectroscopy evidenced that the Ce4+ to Ce3+ reduction occurred just after the application of the cathodic potential; moreover, copper species were reduced to Cu0 during the experiments. The combination of partially reduced CeO2 and Cu particles not only provided selective reaction sites but also increased the electrical conductivity of the electrode. Consequently, the in situ-developed Cu-CeO2 electrocatalysts promoted the selective electrocatalytic hydrogenation of the more concentrated 0.10 M HMF electrolytes, overperforming previously reported AgCu materials at -0.51 V vs RHE

Understanding structure-activity relationships in highly active La promoted Ni catalysts for CO₂ methanation

Ni-based catalysts are selective in the hydrogenation of CO_{2} to CH_{4} but their activity and stability need improvement. Herein, we propose a hydrotalcite-derived high loaded Ni-Al_{2}O_{3} catalyst promoted by La. The effect of La on the catalyst properties is investigated and compared with that of Y and Ce. The NiO_{x} rystallite size and basic properties (rather than the nickel reducibility) as well as the catalytic activity depend on the rare-earth element. The La-catalyst achieves a more relevant activity enhancement at low temperature and high space velocity (480 L g^{-1} h^{-1}, CO_{2}/H_{2}/N_{2} = 1/4/1 v/v), high CH_{4} productivity (101 L_{CH4} gNi^{-1} h^{-1}) and stability, even under undiluted feeds. In situ DRIFTS and the characterization of spent catalysts confirm that this enhanced performance is related to the combination of dissociative and associative CO_{2} activation on more reduced, highly dispersed and stable Ni nanoparticles and basic sites in the La_{2}O_{3}-Al_{2}O_{3} matrix, respectively

Sprouty Proteins Inhibit Receptor-mediated Activation of Phosphatidylinositol-specific Phospholipase C

PLCγ03B3 binds Spry1 and Spry2. Overexpression of Spry decreased PLCγ03B3 activity and IP3 and DAG production, whereas Spry-deficient cells yielded more IP3. Spry overexpression inhibited T-cell receptor signaling and Spry1 null T-cells hyperproliferated with TCR ligation. Through action of PLCγ03B3, Spry may influence signaling through multiple receptors

Osseointegration of implants with dendrimers surface characteristics installed conventionally or with Piezosurgery®. A comparative study in the dog

AIM: The first aim of the present experiment was to compare bone healing at implants installed in recipient sites prepared with conventional drills or a piezoelectric device. The second aim was to compare implant osseointegration onto surfaces with and without dendrimers coatings. MATERIAL AND METHODS: Six Beagles dogs were used in this study. Five implants with two different surfaces, three with a ZirTi(®) surface (zirconia sand blasted, acid etched), and two with a ZirTi(®)-modified surface with dendrimers of phosphoserine and polylysine were installed in the right side of the mandible. In the most anterior region (P2, P3), two recipient sites were prepared with drills, and one implant ZirTi(®) surface and one coated with dendrimers implants were installed at random. In the posterior region (P4 and M1), three recipient sites were randomly prepared: two sites with a Piezosurgery(®) instrument and one site with drill and two ZirTi(®) surface and one coated with dendrimers implants installed. Three months after the surgery, the animals were sacrificed for histological analysis. RESULTS: No complications occurred during the healing period. Three implants were found not integrated and were excluded from analysis. However, n = 6 was obtained. The distance IS-B at the buccal aspect was 2.2 ± 0.8 and 1.8 ± 0.5 mm, while IS-C was 1.5 ± 0.9 and 1.4 ± 0.6 mm at the Piezosurgery(®) and drill groups, respectively. Similar values were obtained between the dendrimers-coated and ZirTi(®) surface implants. The BIC% values were higher at the drill (72%) compared to the Piezosurgery(®) (67%) sites. The BIC% were also found to be higher at the ZirTi(®) (74%) compared to the dendrimers-coated (65%) implants, the difference being statistically significant. CONCLUSION: This study has revealed that oral implants may osseointegrate equally well irrespective of whether their bed was prepared utilizing conventional drills with abundant cooling or Piezosurgery(®). Moreover, the surface coating of implants with dendrimers phosphoserine and polylysine did not improve osseointegration