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Frailty, as quantified by the modified frailty index (mFI), has emerged as a promising method to identify patients at high risk of complications after surgery. Several studies have shown that frailty, as opposed to age, is more predictive of adverse surgical outcomes. We hypothesized that a 5-item mFI could be used to identify patients at elevated risk of complications after total shoulder arthroplasty (TSA). We identified patients aged 50 years or older who underwent TSA in the American College of Surgeons National Surgical Quality Improvement Program database. Pearson χ2 analysis and linear regression were used to determine the association of the mFI score with 30-day postoperative complications, reoperation, readmission, length of stay (LOS), adverse hospital discharge, and mortality rate. The study included 9861 patients with a mean age of 70 years. As the mFI score increased from 0 to 2 or greater, the following rates increased: postoperative complications from 4.2% to 9.4%, readmission from 1.6% to 4.4%, adverse hospital discharge from 6.3% to 19.6%, and LOS from 1.88 days to 2.43 days (P <.001). Multivariate analysis showed that patients with an mFI score of 2 or greater were over twice as likely to sustain a postoperative complication (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.86-3.10), readmission (OR, 2.80; 95% CI, 1.88-4.17), reoperation (OR, 1.82; 95% CI, 1.02-3.25), and adverse hospital discharge (OR, 3.14; 95% CI, 2.51-3.92). These effects were all significantly higher compared with age. Frailty is associated with increased rates of 30-day postoperative complications, readmission, reoperation, adverse hospital discharge, and hospital LOS after TSA. Use of a simple frailty evaluation may help inform decision making and risk assessment when considering TSA. [ABSTRACT FROM AUTHOR]

The cortisol awakening response (CAR) is often assessed in the saliva and considered to be representative of serum cortisol. However, free cortisol is rapidly converted into cortisone as it passes from the serum into the saliva. Because of this enzymatic conversion, the salivary cortisone awakening response (EAR) may be more closely related to serum cortisol dynamics than the salivary CAR. Therefore, the purpose of this study was to measure the EAR and CAR in saliva and compare it to the serum CAR. Male participants (n = 12) had an intravenous catheter placed for serial serum sampling and completed two overnight laboratory sessions, wherein participants slept in the laboratory and saliva and serum samples were collected every 15 min after volitional awakening the following morning. Serum was assayed for total cortisol and saliva for cortisol and cortisone. The CAR and EAR was assessed in saliva and the CAR in serum via mixed-effects growth models and common awakening response indices (area under the curve [AUC] relative to the ground [AUC G ] and relative to the increase [AUC I ], and change scores [Δ]). There was a distinct rise in salivary cortisone following awakening demonstrating the presence of a discernable EAR (β Quadratic = −41.18, [95%CI = −68.90 to −13.46], p < 0.004, Conditional R2 = 0.641). Two EAR indices (AUC G : p < 0.001 and AUC I : p = 0.030) were associated with the corresponding serum CAR indices. We demonstrate for the first time a distinct cortisone awakening response. The results suggest the EAR may be more closely related to serum cortisol dynamics during the post-awakening period, and thus, may be a biomarker of interest in addition to the CAR for assessing hypothalamic-pituitary-adrenal axis functioning. • This is one of the first studies to explicity test for and demonstrate the presence of a cortisone awakening response. • The cortisone awakening response is associated with blood-based cortisol awakening response. • Researchers should consider cortisone as an alternative hormone for assessing salivary awakening responses. [ABSTRACT FROM AUTHOR]

The cortisol awakening response (CAR) describes the increase in cortisol within the first 30–60 min after waking from nocturnal sleep, and is a common biomarker used within psychoneuroendocrinology, but the effect of sleep on the CAR is currently unclear. A previous study suggested that reported discrepancies may be due to other lifestyle behaviors such as physical activity; given the role of the CAR in energy regulation and preparation for the day, it is theoretically plausible that activity level would influence the CAR. However, no study has yet utilized objective monitoring of day-to-day sleep and physical activity to investigate potential effects on the CAR. This study aimed to test the hypotheses that either sleep duration or sleep quality would interact with the prior 24 h′ physical activity to predict the CAR on the following morning. Salivary samples were collected from 85 young adults (mean = 19.1 years, SD = 1.89) immediately after waking from nocturnal sleep and again 30 min after waking; two complete and consecutive days were used. Participants wore accelerometers (ActiGraph, wGT3X-BT) throughout this phase of a larger study, which provided objective measures of sleep duration, number of awakenings, and amount of physical activity. Mixed-effects models with post-hoc regions of significance decompositions tested the hypothesized interaction effects. Results demonstrated a significant interaction between prior day sleep duration and physical activity predicting the next day CAR, wherein short sleep duration and high levels of physical activity resulted in an augmented CAR. Although more sleep clearly predicted a smaller next day CAR in main effect, this study provides additional support that sleep duration effects are also moderated by prior day physical activity. Both behavioral factors should be considered when assessing the CAR and the association between the CAR other psychoneuroendocrine outcomes. • The interaction of objectively measured previous day sleep duration and physical activity predicts the CAR. • The interaction of physical activity and sleep quality, as assessed by the number of awakenings, does not predict the CAR. • Short sleep durations coupled with high levels of physical activity was related to an augmented CAR. • Future investigations of the CAR should consider the effect of physical activity when investigating sleep parameters. [ABSTRACT FROM AUTHOR]

Optical, electrical, and mass spectrometry experiments were carried out on solution grown GaN crystals to detect and identify the impurities incorporated in faces of different polarity at different growth condition. Selective etching, photoluminescence and cathodoluminescence imaging indicate that Mg acceptors incorporate preferentially in GaN nitrogen polar face. Larger incorporation of Mg was observed on crystals grown at lower temperatures. Capacitance–voltage measurements verified p-type conductivity due to an excess of Mg acceptors on N-polar face of the GaN crystals. These results suggest that epitaxial layers deposited from liquid phase may be the best approach to produce p-type conducting layers with high hole concentration and low defect density. [ABSTRACT FROM AUTHOR]

Studies of diamond material for thermal management are reported for a nominally 1-µm thick layer grown on silicon. Thickness of the diamond is measured using spectroscopic ellipsometry. Spectra are consistently modeled using a diamond layer taking into account surface roughness and requiring an interlayer of nominally silicon carbide. The presence of the interlayer is confirmed by transmission electron microscopy. Thermal conductivity is determined based on a heater which is microfabricated followed by back etching to produce a supported diamond membrane. Micro-Raman mapping of the diamond phonon is used to estimate temperature rise under known drive conditions of the resistive heater. Consistent values are obtained for thermal conductivity based on straightforward analytical calculation using phonon shift to estimate temperature and finite element simulations which take both temperature rise and thermal stress into account. [ABSTRACT FROM AUTHOR]

The in-plane thermal conductivity of polycrystalline diamond near its nucleation site, which is a key parameter to an efficient integration of diamond in modern high power AlGaN/GaN high electron mobility devices, has been studied. By controlling the lateral grain size evolution through the diamond growth conditions it has been possible to increase the in-plane thermal conductivity of the polycrystalline diamond film for a given thickness. Besides, the in-plane thermal conductivity has been found strongly inhomogeneous across the diamond films, being also possible to control this inhomogeneity by the growth conditions. The experimental results has been explained through a combined effect of the phonon mean free path confinement due the grain size and the quality of the grain/grain interfaces, showing that both effects evolve with the grain expansion and are dependant on the diamond growth conditions. This analysis shows how the thermal transport in the near nucleation region of polycrystalline diamond can be controlled, which ultimately opens the door to create ultra-thin layers with a engineered thermal conductivity, ranging from a few W/m K to a few hundreds of W/m K. [ABSTRACT FROM AUTHOR]

In situ X-Ray Absorption Near Edge Spectroscopy (XANES) and Extended X-Ray Absorption Fine Structure (EXAFS) techniques are applied to a metal center ionic liquid undergoing oxidation and reduction in a three electrode spectroscopic cell. Determination of the extent of reduction under negative bias on the working electrode and the extent of oxidation are determined after pulse voltammetry to quiescence. While the ionic liquid undergoes full oxidation, it undergoes only partial reduction, likely due to transport issues on the timescale of the experiment. Nearest neighbor Fe-O distances in the fully oxidized state match well to expected values for similarly coordinated solids, but reduction does not result in an extension of the Fe-O bond length, as would be expected from comparisons to the solid phase. Instead, little change in bond length is observed. We suggest that this may be due to a more complex interaction between the monodentate ligands of the metal center anion and the surrounding charge cloud, rather than straightforward electrostatics between the metal center and the nearest neighbor grouping. [ABSTRACT FROM AUTHOR]

A pair of redox flow batteries containing polyoxometalates was tested as part of an ongoing program in stationary energy storage. The iron-containing dimer, (SiFe3W9(OH)3O34)2(OH)311-, cycled between (SiFe3W9(OH)3O34)2(OH)311-/(SiFe3W9(OH)3O34)2(OH)314-and (SiFe3W9(OH)3O34)2(OH)317-/(SiFe3W9(OH)3O34)2(OH)314- for the positive and negative electrode, respectively. This compound demonstrated a coulombic efficiency of 83% after 20 cycles with an electrochemical yield (measured discharge capacity as a percentage of theoretical capacity) of 55%. Cyclic voltammetry on the Lindqvist ion, cis-V2W4O194-, showed quasi-reversible vanadium electrochemistry, but tungsten reduction was mostly irreversible. In a flow cell configuration, cis-V2W4O194-had a coulombic efficiency of 45% (for a two-electron process) and an electrochemical yield of 16% after 20 cycles. The poor performance of cis-V2W4O194-was attributed primarily to its higher charge density. Collectively, the results showed that both polyoxometalate size and charge density are both important parameters to consider in battery material performance. [ABSTRACT FROM AUTHOR]