672 research outputs found
Why we can't help working when ill: the perverse causes of presenteeism in the UK, with a focus on prison officers and academics
The term ‘presenteeism’ refers to situations where employees continue to attend work while they are sick. In this report we look at why absenteeism policies can encourage presenteeism and how presenteeism presents in two working populations: UK prison officers and UK academics
Multiplet resonance lifetimes in resonant inelastic X-ray scattering involving shallow core levels
Resonant inelastic X-ray scattering (RIXS) spectra of model copper- and
nickel-based transition metal oxides are measured over a wide range of energies
near the M-edge (h=60-80eV) to better understand the properties of
resonant scattering involving shallow core levels. Standard multiplet RIXS
calculations are found to deviate significantly from the observed spectra.
However, by incorporating the self consistently calculated decay lifetime for
each intermediate resonance state within a given resonance edge, we obtain
dramatically improved agreement between data and theory. Our results suggest
that these textured lifetime corrections can enable a quantitative
correspondence between first principles predictions and RIXS data on model
multiplet systems. This accurate model is also used to analyze resonant elastic
scattering, which displays the elastic Fano effect and provides a rough upper
bound for the core hole shake-up response time.Comment: 6 pages, 3 figure
Disorder enabled band structure engineering of a topological insulator surface
Three dimensional topological insulators are bulk insulators with
topological electronic order that gives rise to conducting
light-like surface states. These surface electrons are exceptionally resistant
to localization by non-magnetic disorder, and have been adopted as the basis
for a wide range of proposals to achieve new quasiparticle species and device
functionality. Recent studies have yielded a surprise by showing that in spite
of resisting localization, topological insulator surface electrons can be
reshaped by defects into distinctive resonance states. Here we use numerical
simulations and scanning tunneling microscopy data to show that these resonance
states have significance well beyond the localized regime usually associated
with impurity bands. At native densities in the model BiX (X=Bi, Te)
compounds, defect resonance states are predicted to generate a new quantum
basis for an emergent electron gas that supports diffusive electrical
transport
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Modification of Transition-Metal Redox by Interstitial Water in Hexacyanometalate Electrodes for Sodium-Ion Batteries.
A sodium-ion battery (SIB) solution is attractive for grid-scale electrical energy storage. Low-cost hexacyanometalate is a promising electrode material for SIBs because of its easy synthesis and open framework. Most hexacyanometalate-based SIBs work with aqueous electrolyte, and interstitial water in the material has been found to strongly affect the electrochemical profile, but the mechanism remains elusive. Here we provide a comparative study of the transition-metal redox in hexacyanometalate electrodes with and without interstitial water based on soft X-ray absorption spectroscopy and theoretical calculations. We found distinct transition-metal redox sequences in hydrated and anhydrated NaxMnFe(CN)6·zH2O. The Fe and Mn redox in hydrated electrodes are separated and are at different potentials, leading to two voltage plateaus. On the contrary, mixed Fe and Mn redox in the same potential range is found in the anhydrated system. This work reveals for the first time how transition-metal redox in batteries is strongly affected by interstitial molecules that are seemingly spectators. The results suggest a fundamental mechanism based on three competing factors that determine the transition-metal redox potentials. Because most hexacyanometalate electrodes contain water, this work directly reveals the mechanism of how interstitial molecules could define the electrochemical profile, especially for electrodes based on transition-metal redox with well-defined spin states
Pharmacological Interventions in Labor and Delivery
While there is not a wide range of pregnancy-specific drugs, there are some very specific high-risk areas of obstetric care for which unique pharmacological approaches have been established. In preterm birth, labor induction and augmentation, and the management of postpartum hemorrhage, these pharmacological approaches have become the bedrock in managing some of the most common and problematic areas of antenatal and intrapartum care. In this review, we summarize the existing established and emerging evidence that supports and broadens these pharmacological approaches to obstetric management and its impact on clinical practice. It is clear that existing therapeutics are limited. They have largely been developed from our knowledge of the physiology of the myometrium and act on hormonal receptors and their signaling pathways or on ion channels influencing excitability. Newer drugs in development are mostly refinements of these two approaches, but novel agents from plants and improved formulations are also discussed
Elevated cyclic-AMP represses expression of Exchange Protein Activated by cAMP (EPAC1) by inhibiting YAP-TEAD activity and HDAC-mediated histone deacetylation
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