Palladium and cerium oxide nanoparticles obtained by pulsed laser ablation (PLA) in liquid (water or ethanol) have been used as nanostructured precursors for synthesis of the composite Pd/CeO2 catalysts. The initial mixture of Pd and CeO2 nanoparticles does not show catalytic activity at temperatures lower than 100°C. It has been found that the composites prepared by PLA in alcohol are easily activated by calcination in air at 450-600°C demonstrating high activity at room temperature. Application of XRD, TEM and XPS reveals that laser ablation in water leads to the formation of large and well crystallized nanoparticles of palladium and CeO2, whereas ablation in alcohol results in formation of much smaller PdCx nanoparticles. The activation of the composites takes place due to the strong Pd-ceria interaction which occurs easier for highly-dispersed defective particles obtained in alcohol. Such interaction implies the introduction of palladium ions into the ceria lattice with formation of a mixed phase of PdxCe1-xO2-x-δ solid solution at the contact spaces of palladium and cerium oxide nanoparticles. The TPR-CO and XPS data show clearly that on the surface of the PdxCe1-xO2-x-δ solid solution the oxidized PdOx(s)/Pd-O-Ce(s) clusters are formed. These clusters comprise the highly reactive oxygen which is responsible for the high catalytic activity in LTO CO.Please do not adjust margins Please do not adjust margins CO (molecules/cm 3 ), X is the CO conversion, V RM is the reaction mixture rate (cm 3 /sec), m is the weight of the sample (g), and

Here, we report on ZnO nanoparticles (NPs) generated by nanosecond pulsed laser (Nd:YAG, 1064 nm) through ablation of metallic Zn target in water and air and their comparative analysis as potential nanomaterials for biomedical applications. The prepared nanomaterials were carefully characterized in terms of their structure, composition, morphology and defects. It was found that in addition to the main wurtzite ZnO phase, which is conventionally prepared and reported by others, the sample laser generated in air also contained some amount of monoclinic zinc hydroxynitrate. Both nanomaterials were then used to modify model wound dressings based on biodegradable poly l-lactic acid. The as-prepared model dressings were tested as biomedical materials with bactericidal properties towards S. aureus and E. coli strains. The advantages of the NPs prepared in air over their counterparts generated in water found in this work are discussed.

The pulsed laser ablation (PLA) in alcohol and water media was employed to prepare Pt and CeO2 PLA‐nanoparticles of different sizes and degrees of defectiveness. Interactions of metallic platinum and ceria particles were studied using the thermal activation of Pt–CeO2 mechanical mixtures in the CO+O2 reaction medium or O2 atmosphere. The thermal activation resulted in oxidized Pt2+/Pt4+ states of platinum in the surface solid solutions PtCeOx and/or PtOx clusters. Catalysts formed after calcination of the PLA‐ablated Pt–CeO2 mixtures in oxygen at 450–600 °C revealed CO conversion at very low temperatures up to 70 % depending on the conditions of PLA particles preparation and thermal activation of Pt–CeO2 mechanical mixture.

No abstract

Glioblastoma (GBM) is the most aggressive primary brain tumor in adults. Despite progress in surgical and medical neuro-oncology, prognosis for GBM patients remains dismal, with a median survival of only 14-15 months. The modest benefit of conventional therapies is due to the presence of GBM stem cells (GSCs) that cause tumor relapse and chemoresistance and, therefore, that play a key role in GBM aggressiveness and recurrence. So far, strategies to identify and target GSCs have been unsuccessful. Thus, the development of an approach for GSC detection and targeting would be fundamental for improving the survival of GBM patients. Here, using the cell-systematic evolution of ligand by exponential (SELEX) methodology on human primary GSCs, we generated and characterized RNA aptamers that selectively bind GSCs versus undifferentiated GBM cells. We found that the shortened version of the aptamer 40L, which we have called A40s, costained with CD133-labeled cells in human GBM tissue, suggestive of an ability to specifically recognize GSCs in fixed human tissues. Of note, both 40L and A40s were rapidly internalized by cells, allowing for the delivery of the microRNA miR-34c and the anti-microRNA anti-miR-10b, demonstrating that these aptamers can serve as selective vehicles for therapeutics. In conclusion, the aptamers 40L and A40s can selectively target GSCs. Given the crucial role of GSCs in GBM recurrence and therapy resistance, these aptamers represent innovative drug delivery candidates with a great potential in the treatment of GBM.