Electrooxidation of C-4 polyols on platinum single- crystals: a computational and electrochemical study

Many polyols are abundant and cheap molecules highly spread in the biomass. These molecules have an enormous potential to be used in electrochemical devices to generate energy and/or value-added molecules. The electrooxidation of polyols can produce different substances of interest in the chemical industry concomitantly to high purity hydrogen in electrolyzers. The cost in the production of all these chemicals depends, among other factors, on the develop of more active and selective catalysts. However, in order to search for these materials using computational experiments, it is mandatory to have a better understanding of the fundamental aspect of the reactions, which permit to base the search on the adsorption energies of one or more key reaction intermediates. To contribute to this task, we performed (spectro)-electrochemical and computational experiments to study the electrooxidation of C-4 polyols. We show that the electrooxidation of polyols does not depend on the relative orientation of their OH groups. Besides, using Pt single crystals, we demonstrate that the trend for the oxidation of the primary carbon (relative to the secondary) increases in the order Pt(111) < Pt(100) < Pt(110) and that this result can be extended to polyols with longer carbon chains. Finally, computational experiments permit us to rationalize these trends looking at the relative stability of double dehydrogenated intermediates on the Pt basal planes.Catalysis and Surface Chemistr

Comparison of estimated glomerular filtration rate (eGFR) using the MDRD and CKD-EPI equations for CKD screening in a large population

Background/Aims Recently, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) proposed a new equation for estimating glomerular filtration rate (eGFR), which could potentially replace the Modified Diet for Renal Disease Study (MDRD) equation in routine clinical use Our aim was to evaluate the correlation between them and to compare the prevalence of each CKD stage using these two equations Methods We measured serum creatinine in 38,188 consecutive patients and calculated eGFR using the CKD-EPI and MDRD equations We also compared the distribution of CKD stages for both equations Results There was very good correlation between eGFR estimated by CKD-EPI and MDRD at values < 60 ml/min x 1 73 m(2), but not at higher values Estimated prevalence of CKD (eGFR < 60 ml/min x 1 73 m2) was 5 9% with CKD-EPI and 7 5% with MDRD Furthermore, the prevalence of CKD Stage 2 was lower with CKD-EPI (33 8% vs 49 1% with MDRD) Conclusion The use of the CKD-EPI equation results in a lower estimated prevalence of CKD, compared to the MDRD equation This may have important implications for public health and clinical practice, as well as for future modification of guidelines for laboratorie

Are homes for the elderly still a risk area for HBV infection?

To verify whether improvements in hygiene affect the risk of HBV infection, a seroepidemiological survey on HBV infection was carried out in a home for the elderly with continuous-care accommodation. HBV serum markers were tested in 315 subjects and the results of HBV infection were compared to those observed in two different types of nursing homes for the elderly from an earlier seroepidemiological study carried out in 1978. In addition, results from a cohort of a pre-geriatric population living in their own homes in the same geographical area surveyed in 1980 were compared to the present study. A statistically significant lower prevalence of HBV serum markers in the new home for the elderly compared to the two types studied in 1978 was observed. No difference was found between the new institutionalized study group and the cohort of a pre-geriatric population surveyed in 1980. These results reflect the improved sanitation in homes for the elderly and show that the elderly have very few opportunities to become infected, even in a close cohabitation syste

Neurally adjusted ventilatory assist: a new approach to mechanically ventilated infants

Neurally adjusted ventilator assist (NAVA) is a new mode of partial ventilatory support, in which neural inspiratory activity is monitored through the continuous esophageal recording of the electrical activity of the diaphragm. Assistance is triggered and cycled off in according to this signal and is delivered in proportion to its intensity. NAVA can improve patient-ventilator synchrony while maintaining spontaneous breathing. Small preliminary studies have shown that NAVA can be successfully used also in term and preterm infants, being safe and well tolerated. However, much additional work is still needed before NAVA can be recommended in the everyday practice of the neonatologist