Microstructural strain energy of α-uranium determined by calorimetry and neutron diffractometry

The microstructural contribution to the heat capacity of α-uranium was determined by measuring the heat-capacity difference between polycrystalline and single-crystal samples from 77 to 320 K. When cooled to 77 K and then heated to about 280 K, the uranium microstructure released (3±1) J/mol of strain energy. On further heating to 300 K, the microstructure absorbed energy as it began to redevelop microstrains. Anisotropic strain-broadening parameters were extracted from neutron-diffraction measurements on polycrystals. Combining the strain-broadening parameters with anisotropic elastic constants from the literature, the microstructural strain energy is predicted in the two limiting cases of statistically isotropic stress and statistically isotropic strain. The result calculated in the limit of statistically isotropic stress was (3.7±0.5) J/mol K at 77 K and (1±0.5) J/mol at room temperature. In the limit of statistically isotropic strain, the values were (7.8±0.5) J/mol K at 77 K and (4.5±0.5) J/mol at room temperature. In both cases the changes in the microstructural strain energy showed good agreement with the calorimetry

Fast-track pathway for elective caesarean section: a quality improvement initiative to promote day 1 discharge.

Enhanced recovery after surgery (ERAS) aims to improve perioperative care, hasten recovery to the normal physiological state and shorten length of stay (LoS). There is evidence that ERAS programmes following elective caesarean section (ELCS) confer benefit through faster return to physiological state and reduced LoS for mother and baby. Baseline audit of ELCS in 2013 revealed a mean LoS of 3 days. We piloted an ERAS discharge pathway promoting day 2 discharge, which rose from 5.0% to 40.2%. 19.2% of women went home on day 1. Many women fed back that they would prefer day 1 discharge. We hypothesised that a day 1 discharge pathway for low-risk women could benefit both women and services at our maternity unit. From October 2015, we developed a 'fast-track pathway' (FTP) using a Plan-Do-Study-Act approach. Between October 2015 and April 2016, we prospectively audited clinical outcomes, LoS and maternal satisfaction from all women placed on the FTP. We held regular multidisciplinary team meetings to allow contemporaneous analysis. Satisfaction was analysed by Likert scale at postoperative surveys. Women were identified in antenatal clinic after meeting predefined low-risk criteria. 27.3% of women (n=131/479) delivering by ELCS entered the FTP. 76.2% of women on the FTP were discharged on day 1. Mean LoS fell to 1.31 days. 94.2% of women who established breast feeding at day 1 were still breast feeding at 7 days. Overall satisfaction at day 7 was 4.71 on a 5-point Likert scale. 73.1% of women reported good pain control. Additional financial savings are estimated at £99 886 annually. There were no related cases of readmission. Day 1 discharge after ELCS is safe and acceptable in carefully selected, low-risk women and has high satisfaction. There may be resultant financial savings and improved flow through a maternity unit with no detected adverse effect on breast feeding, maternal morbidity or postnatal readmissions

Angle-resolved photoemission and first-principles electronic structure of single-crystalline α\alpha-uranium (001)

Continuing the photoemission study begun with the work of Opeil et al. [Phys. Rev. B \textbf{73}, 165109 (2006)], in this paper we report results of an angle-resolved photoemission spectroscopy (ARPES) study performed on a high-quality single-crystal $\alpha$-uranium at 173 K. The absence of surface-reconstruction effects is verified using X-ray Laue and low-energy electron diffraction (LEED) patterns. We compare the ARPES intensity map with first-principles band structure calculations using a generalized gradient approximation (GGA) and we find good correlations with the calculated dispersion of the electronic bands

The influence of surface morphology and oxide microstructure on the nucleation and growth of uranium hydride on alpha uranium

While the bulk kinetics of the uranium-hydrogen reaction are well understood, the mechanisms underlying the initial nucleation of uranium hydride on uranium remain controversial. In this study, the authors have employed environmental cell optical microscopy, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy, (AFM) in an attempt to relate the structure of the surface and the microstructure of the substrate with the susceptibility and site of hydride nucleation. Samples have been investigated with varying grain size, inclusion (carbide) concentration, and thermal history. There is a clear correlation to heat treatment immediately prior to hydrogen exposure. Susceptibility to hydride formation also appears to be related to impurities in the uranium. The oxidized surface is very complex, exhibiting wide variations in thickness and topography between samples, between grains in the same sample, and within individual grains. It is, however, very difficult to relate this fine scale variability to the relatively sparse hydride initiation sites. Therefore, the surface oxide layer itself does not appear to control the sites where hydride attack is initiated, although it must play a role in the induction period prior to hydride initiation

The Influence of Surface Morphology and Oxide Microstructure on the Nucleation and Growth of Uranium Hydride on Alpha Uranium

While the bulk kinetics of the uranium-hydrogen reaction are well understood, the mechanisms underlying the initial nucleation of uranium hydride on uranium remain controversial. In this study, the authors have employed environmental cell optical microscopy, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy, (AFM) in an attempt to relate the structure of the surface and the microstructure of the substrate with the susceptibility and site of hydride nucleation. Samples have been investigated with varying grain size, inclusion (carbide) concentration, and thermal history. There is a clear correlation to heat treatment immediately prior to hydrogen exposure. Susceptibility to hydride formation also appears to be related to impurities in the uranium. The oxidized surface is very complex, exhibiting wide variations in thickness and topography between samples, between grains in the same sample, and within individual grains. It is, however, very difficult to relate this fine scale variability to the relatively sparse hydride initiation sites. Therefore, the surface oxide layer itself does not appear to control the sites where hydride attack is initiated, although it must play a role in the induction period prior to hydride initiation

Potential sites of CFTR activation by tyrosine kinases

The CFTR chloride channel is tightly regulated by phosphorylation at multiple serine residues. Recently it has been proposed that its activity is also regulated by tyrosine kinases, however the tyrosine phosphorylation sites remain to be identified. In this study we examined 2 candidate tyrosine residues near the boundary between the first nucleotide binding domain and the R domain, a region which is important for channel function but devoid of PKA consensus sequences. Mutating tyrosines at positions 625 and 627 dramatically reduced responses to Src or Pyk2 without altering the activation by PKA, suggesting they may contribute to CFTR regulation

Process analysis of the patient pathway for automated data collection: an exemplar using pituitary surgery

Introduction: Automation of routine clinical data shows promise in relieving health systems of the burden associated with manual data collection. Identifying consistent points of documentation in the electronic health record (EHR) provides salient targets to improve data entry quality. Using our pituitary surgery service as an exemplar, we aimed to demonstrate how process mapping can be used to identify reliable areas of documentation in the patient pathway to target structured data entry interventions. Materials and methods: This mixed methods study was conducted in the largest pituitary centre in the UK. Purposive snowball sampling identified frontline stakeholders for process mapping to produce a patient pathway. The final patient pathway was subsequently validated against a real-world dataset of 50 patients who underwent surgery for pituitary adenoma. Events were categorized by frequency and mapped to the patient pathway to determine critical data points. Results: Eighteen stakeholders encompassing all members of the multidisciplinary team (MDT) were consulted for process mapping. The commonest events recorded were neurosurgical ward round entries (N = 212, 14.7%), pituitary clinical nurse specialist (CNS) ward round entries (N = 88, 6.12%) and pituitary MDT treatment decisions (N = 88, 6.12%) representing critical data points. Operation notes and neurosurgical ward round entries were present for every patient. 43/44 (97.7%) had a pre-operative pituitary MDT entry, pre-operative clinic letter, a post-operative clinic letter, an admission clerking entry, a discharge summary, and a post-operative histopathology pituitary multidisciplinary (MDT) team entries. Conclusion: This is the first study to produce a validated patient pathway of patients undergoing pituitary surgery, serving as a comparison to optimise this patient pathway. We have identified salient targets for structured data entry interventions, including mandatory datapoints seen in every admission and have also identified areas to improve documentation adherence, both of which support movement towards automation

Can Modal Skepticism Defeat Humean Skepticism?

My topic is moderate modal skepticism in the spirit of Peter van Inwagen. Here understood, this is a conservative version of modal empiricism that severely limits the extent to which an ordinary agent can reasonably believe “exotic” possibility claims. I offer a novel argument in support of this brand of skepticism: modal skepticism grounds an attractive (and novel) reply to Humean skepticism. Thus, I propose that modal skepticism be accepted on the basis of its theoretical utility as a tool for dissolving philosophical paradox