Potentiometric Hydrogen Sensor with 3D-Printed BaCe0.6Zr0.3Y0.1O3-α Electrolyte for High-Temperature Applications.

Hydrogen is expected to play an important role in the near future in the transition to a net-zero economy. Therefore, the development of new in situ and real-time analytical tools able to quantify hydrogen at high temperatures is required for future applications. Potentiometric sensors based on perovskite-structured solid-state electrolytes can be a good option for H2 monitoring. Nevertheless, the geometry of the sensor should be designed according to the specific necessities of each technological field. Conventional shaping processes need several iterations of green shaping and machining to achieve a good result. In contrast, 3D printing methods stand out from conventional ones since they simplify the creation of prototypes, reducing the cost and the number of iterations needed for the obtainment of the final design. In the present work, BaCe0.6Zr0.3Y0.1O3-α (BCZY) was used as a proton-conducting electrolyte for potentiometric sensors construction. Two different shapes were tested for the sensors' electrolyte: pellets (BCZY-Pellet) and crucibles (BCZY-Crucible). Ceramics were shaped using extrusion-based 3D printing. Finally, parameters, such as sensitivity, response time, recovery time and the limit of detection and accuracy, were evaluated for both types of sensors (BCZY-Pellet and BCZY-Crucible) at 500 °C.

In Vitro and In Vivo Antimicrobial Activity of Hypochlorous Acid against Drug-Resistant and Biofilm-Producing Strains.

The aims of this study were as follows. First, we determined the antimicrobial efficacy of hypochlorous acid (HClO) against bacterial, fungal, and yeast strains growing planktonically and growing in biofilms. Second, we sought to compare the activity of the combination of daptomycin and HClO versus those of the antimicrobial agents alone for the treatment of experimental catheter-related Staphylococcus epidermidis infection (CRI) using the antibiotic lock technique (ALT) in a rabbit model. HClO was generated through direct electric current (DC) shots at determined amperages and times. For planktonic susceptibility studies, 1 to 3 DC shots of 2, 5, and 10 mA from 0 to 300 s were applied. A DC shot of 20 mA from 0 to 20 min was applied to biofilm-producing strains. Central venous catheters were inserted into New Zealand White rabbits, inoculated with an S. epidermidis strain, and treated with saline solution or ALT using daptomycin (50 mg/mL), HClO (20 mA for 45 min), or daptomycin plus HClO. One hundred percent of the planktonic bacterial, fungal, and yeast strains were killed by applying one DC shot of 2, 5, and 10 mA, respectively. One DC shot of 20 mA for 20 min was sufficient to eradicate 100% of the tested biofilm-producing strains. Daptomycin plus HClO lock therapy showed the highest activity for experimental CRI with S. epidermidis. HClO could be an effective strategy for treating infections caused by extensively drug-resistant or multidrug-resistant and biofilm-producing strains in medical devices and chronic wounds. The results of the ALT using daptomycin plus HClO may be promising. IMPORTANCE Currently, drug-resistant infections are increasing and there are fewer antibiotics available to treat them. Therefore, there is an urgent need to find new antibiotics and nonantimicrobial strategies to treat these infections. We present a new nonantibiotic strategy based on hypochlorous acid generation to treat long-term catheter-related and chronic wounds infections.