No abstract

Several reports have been made recently of the direct formate fuel cell (DFFC) operating at high-temperature and using Pt cathode catalyst. In the present work, we demonstrate a Pt-free DFFC employing ACTA HypermecTM 4020 Fe–Co second-generation cathode catalyst operating at low-temperature. We report a maximum power density (PD) of 45 mW cm−2 at ambient temperature (20 °C), when the fuel stream was 1 M HCOOK and 2 M KOH with oxygen used at the cathode. When air was used at the cathode, the maximum PD was 35 mW cm−2. When hydroxide was removed from the fuel stream and oxygen used at the cathode, the maximum PD at 20 °C was 18 mW cm−2. This low-temperature, KOH-free operation is important to development of a practical DFFC.

Aim: Modern clinical caries management involves early stage caries diagnosis and should fit with dental health policy. The objective of this study was to achieve early caries detection in enamel and dentine with a laser-based system (DIAGNOdent™ pen) first and secondary with a new fluorescence intra-oral camera (Soprolife®). A visual inspection with a loupe was used as control. Materials and methods: Following the consolidated standards of reporting trials recommendations, 628 occlusal fissures were included for analysis. Results: The sensitivity and specificity of both devices varied depending on the cutoff threshold of the caries score, and the ROC curve showed higher values for the Soprolife® than for DIAGNOdent™ pen. The values of the area under the curve decreased from 0.81 (Soprolife® in daylight) to 0.79 (Soprolife® in fluorescent mode) and 0.67 for DIAGNOdent™ pen. DIAGNOdent™ pen reproducibility (intra and inter-investigator) showed a wide dispersion, with many values scattered beyond the confidence limits (±2 SD), and the weighted kappa coefficient, which was quite low (0.58), confirmed this tendency. Conclusion:Caries prevalence in terms of public health policy is of interest and caries detection increased significantly when using an fluorescence-based intra-oral camera. Clinical significance: The clinical significance of these findings is that fluorescence could help improve caries diagnosis, reduce clinical misinterpretations, and finally benefit the patients.