Partial oxidation of Step-Bound Water Leads to Anomalous pH Effects on Metal Electrode Step-Edges

The design of better heterogeneous catalysts for applications such as fuel cells and electrolyzers requires a mechanistic understanding of electrocatalytic reactions and the dependence of their activity on operating conditions such as pH. A satisfactory explanation for the unexpected pH dependence of electrochemical properties of platinum surfaces has so far remained elusive, with previous explanations resorting to complex co-adsorption of multiple species and resulting in limited predictive power. This knowledge gap suggests that the fundamental properties of these catalysts are not yet understood, limiting systematic improvement. Here, we analyze the change in charge and free energies upon adsorption using density-functional theory (DFT) to establish that water adsorbs on platinum step edges across a wide voltage range, including the double-layer region, with a loss of approximately 0.2 electrons upon adsorption. We show how this as-yet unreported change in net surface charge due to this water explains the anomalous pH variations of the hydrogen underpotential deposition (Hupd) and the potentials of zero total charge (PZTC) observed in published experimental data. This partial oxidation of water is not limited to platinum metal step edges, and we report the charge of the water on metal step edges of commonly used catalytic metals, including copper, silver, iridium, and palladium, illustrating that this partial oxidation of water broadly influences the reactivity of metal electrodes.Comment: 9 pages, 8 figures and 3 table

The Prevalence and Impact of Chronic Pain in Baccalaureate Nursing Students

Chronic pain is a problem because it can have a large impact on activities of daily life of people, regardless of age. Few researchers have described the prevalence and impact of chronic pain in young adults, while even fewer have done so in the United States. The purpose of this study is to determine the prevalence of chronic pain and the impact it has on daily life for undergraduate nursing students. The theoretical framework is guided on the biopsychosocial model of chronic pain. This cross-sectional, descriptive study uses convenience sampling and data collected through an online Qualtrics survey, which was embedded in three waves of recruitment emails. Self-reporting responses were collected from 80 subjects who completed a survey with a revised version of the Fibromyalgia Daily Activity Checklist scale. The study found that 30% of undergraduate nursing students surveyed experienced chronic pain. The study also found that chronic pain had a significant impact on daily life, with approximately 68% of those reporting chronic pain also reporting some level of difficulty when performing activities of daily living. This is significant for young adults, especially healthcare students and providers because working as healthcare professional can be physically demanding

JDFTx: software for joint density-functional theory

Density-functional theory (DFT) has revolutionized computational prediction of atomic-scale properties from first principles in physics, chemistry and materials science. Continuing development of new methods is necessary for accurate predictions of new classes of materials and properties, and for connecting to nano- and mesoscale properties using coarse-grained theories. JDFTx is a fully-featured open-source electronic DFT software designed specifically to facilitate rapid development of new theories, models and algorithms. Using an algebraic formulation as an abstraction layer, compact C++11 code automatically performs well on diverse hardware including GPUs. This code hosts the development of joint density-functional theory (JDFT) that combines electronic DFT with classical DFT and continuum models of liquids for first-principles calculations of solvated and electrochemical systems. In addition, the modular nature of the code makes it easy to extend and interface with, facilitating the development of multi-scale toolkits that connect to ab initio calculations, e.g. photo-excited carrier dynamics combining electron and phonon calculations with electromagnetic simulations.Comment: 9 pages, 3 figures, 2 code listing

Hepatitis E in Italy: a silent presence

Hepatitis E virus (HEV) was discovered in the 1980s and has been considered as being confined to developing countries. The purpose of this critical review was to determine the reported HEV seroprevalence rates in Italy, to identify predisposing factors and individuals at risk and to assess possible importation of HEV by immigrants. A critical review of 159 articles published in PubMed from 1994 to date was done. Only 27 original reports of 50 or more subjects, written in the English or Italian language, were included. Over three decades, the HEV seroprevalence varied from 0.12% to 49%, with the highest rates being reported from the central region of Italy. Risk factors included ingestion of raw pork or potentially contaminated food. The seroprevalence among immigrants ranged from 15.3% to 19.7% in Apulia. Italy has a population of 60 656 000; the total number of individuals surveyed was only 21.882 (0.036%). A national epidemiological survey program is needed to capture more comprehensive seroprevalence data. Keywords: Hepatitis E infection, Epidemiology, Seroprevalence, Risk factors, Immigrants, Ital