Structural Evolution of Chemically-Driven RuO2 Nanowires and 3-Dimensional Design for Photo-Catalytic Applications

Growth mechanism of chemically-driven RuO2 nanowires is explored and used to fabricate three-dimensional RuO2 branched Au-TiO2 nanowire electrodes for the photostable solar water oxidation. For the real time structural evolution during the nanowire growth, the amorphous RuO2 precursors (Ru(OH)(3)center dot H2O) are heated at 180 degrees C, producing the RuO2 nanoparticles with the tetragonal crystallographic structure and Ru enriched amorphous phases, observed through the in-situ synchrotron x-ray diffraction and the high-resolution transmission electron microscope images. Growth then proceeds by Ru diffusion to the nanoparticles, followed by the diffusion to the growing surface of the nanowire in oxygen ambient, supported by the nucleation theory. The RuO2 branched Au-TiO2 nanowire arrays shows a remarkable enhancement in the photocurrent density by approximately 60% and 200%, in the UV-visible and Visible region, respectively, compared with pristine TiO2 nanowires. Furthermore, there is no significant decrease in the device's photoconductance with UV-visible illumination during 1 day, making it possible to produce oxygen gas without the loss of the photoactvity.close1

Tip malposition of peripherally inserted central catheters: a prospective randomized controlled trial to compare bedside insertion to fluoroscopically guided placement

Objective: Peripherally inserted central catheter (PICC) use continues to increase, leading to the development of a blind bedside technique (BST) for placement. The aim of our study was to compare the BST with the fluoroscopically guided technique (FGT), with specific regard to catheter tip position (CTP). Materials and methods: One hundred eighty patients were randomized to either the BST or the FGT. All procedures were done by the same interventional team and included postprocedural chest X-ray to assess CTP. Depending on the international guidelines for optimal CTP, patients were classified in three types: optimal, suboptimal not needing repositioning, and nonoptimal requiring additional repositioning procedures. Fisher's test was used for comparisons. Results: One hundred seventy-one PICCs were successful inserted. In the BST groups, 23.3% of placements were suboptimal and 30% nonoptimal, requiring repositioning. In the FGT group, 5.6% were suboptimal and 1.1% nonoptimal. Thus, suboptimal and nonoptimal CTP were significantly lower in the FGT group (p &lt; 0.001). Conclusion: Tip malposition rates are high when using blind BST, exposing the patient to an increased risk of deep venous thrombosis and catheter malfunction. Using the FGT or emerging technologies that could help tip positioning are recommended, especially for long-term indications. Key points: • Bedside and fluoroscopy guided techniques are commonly used for PICC placement. • Catheter malposition is the major technical issue with the bedside technique. • Catheter malposition occurred in 53% of patients with the bedside technique.</p