Search

The interface of a La0.7Sr0.3MnO3/SrTiO3 bilayer was modulated by introducing 3 unit cells of Ba1-xSrxTiO3 using Combinatorial Pulsed Laser Deposition. A wide range of chemical compositions was studied within the same sample, with BSTx stoichiometry variable from 0.5 to 1 along Y-axis, while the SrTiO3 overlayer thickness was modified along the X direction [Fig. 1(a)]. We performed high-resolution, laboratory-based angle-resolved XPS studies of the BSTx film surface providing information on the thickness and composition of the surface and sub-surface layers. Based on the attenuation of the La 3d corelevel photoemission signal from the La0.7Sr0.3MnO3 bottom layer, the BST layer is 1.2 nm thick. XPS Ba 3d5/2 core-level spectra were acquired at positions corresponding to different nominal Ba/Sr stoichiometry. In all measurements, the Ba 3d5/2 core-level spectra can be represented by two main components, i.e. one component at higher binding energy (BE = 780.54 eV) corresponding to surface contribution and the other one at lower binding energy (BE = 778.92 eV) corresponding to sub-surface contribution (Figs. 2 and 3). Going from normal to 60° emission angle and using a 3-unit cell thick film model, the surface to sub-surface intensity ratio clearly evolves providing evidence of a Ba-rich surfactant. The surfactant effect is more significant for lower nominal Ba stoichiometry.

Background: The development of children's speech, language, and literacy skills is considered to build on a robust and intact speech-processing system, with normally functioning skills at all levels of input and output processing, as well as storage. There are a range of tasks available that assess input and output processing skills, however there are few tasks described in the literature that require a child to reflect on and analyse the internal structure of their own phonological representations. Aims: This paper will describe the development of the Silent Deletion of Phonemes (SDOP) task. This task is designed to assess a child's ability to delete and manipulate sounds silently within their own stored representations while minimizing the impact of any output difficulties. Methods & Procedures: The SDOP task was presented to 69 typically developing mainstream Year 2 children (aged 7;2-8;1 years) as part of a battery of phonological processing skills and literacy measures. Outcomes & Results: Scores for the population of typically developing Year 2 children were normally distributed and above a basal level but not approaching ceiling. Performance on the SDOP was significantly correlated with other measures of phonological processing but not a measure of non-verbal ability. It was most highly correlated with the measure of phonological awareness as expected, as both tasks measure awareness of the internal structure of words. However, the SDOP provided more information about the accuracy and specificity of a child's underlying phonological representations. The SDOP explained a significant amount of concurrent variance in both reading and spelling performance beyond the variance accounted for by the predictors that have been used by researchers to date. In combination, the SDOP and rapid-naming measure accounted for 58.8% of variance in performance on the reading measure and 54.4% of variance in spelling performance. Conclusions & Implications: The SDOP task appears to be a valid and reliable tool to assess the internal structure of a child's stored phonological representations. Profiling phonological representations allows clinicians to explore children's speech-processing skills which may be particularly useful with children with complex literacy difficulties. (Contains 3 figures and 6 tables.)

We have studied the field cycling behavior of microscopic TiN/Hf0.5Zr0.5O2/TiN ferroelectric capacitors using synchrotron-based soft x-ray photoemission electron microscopy. The oxygen vacancy ( V O ) concentration near the top TiN/Hf0.5Zr0.5O2 interface is estimated from the reduction of Hf4+ to Hf3+ as measured in the Hf 4f core level spectra. The V O concentration increases with field cycling and redistributes under the effect of the internal field due to the polarization. Upward pointing polarization slightly depletes the concentration near the top interface, whereas downward polarization causes V O drift toward the top interface. The V O redistribution after wake-up is consistent with shifts in the I–V switching peak. The Schottky barrier height for electrons decreases systematically with cycling in polarization states, reflecting the overall increase in V O . [ABSTRACT FROM AUTHOR]

We employed a multitechnique approach using piezo-force response microscopy and photoemission microscopy to investigate a self-organizing polarization domain pattern in PbTiO3/La0.7Sr0.3MnO3 (PTO/LSMO) nanostructures. The polarization is correlated with the nanostructure morphology as well as with the thickness and Mn valence of the LSMO template layer. On the LSMO dots, the PTO is upwards polarized, whereas outside the nanodots, the polarization appears both strain and interface roughness dependent. The results suggest that the electronic structure and strain of the PTO/LSMO interface contribute to determining the internal bias of the ferroelectric layer. [ABSTRACT FROM AUTHOR]

Lakes are vulnerable to climate change, and warming rates in the Arctic are faster than anywhere on Earth. Fishes are sensitive to changing temperatures, which directly control physiological processes. Food availability should partly dictate responses to climate change because energetic demands change with temperature, but few studies have simultaneously examined temperature and food availability.We used a fully factorial experiment to test effects of food availability and temperature (7.6, 12.7, and 17.4°C; 50 days) on growth, consumption, respiration, and excretion, and effects of temperature (12 and 19.3°C; 27 days) on habitat use and growth of a common, but understudied, mid‐level consumer, slimy sculpin Cottus cognatus, in arctic lakes. We also used bioenergetics modelling to predict consumptive demand under future warming scenarios.Growth rates were 3.4× higher at 12.7°C in high food compared to low food treatments, but the magnitude of differences depended on temperature. Within low food treatments, there was no statistical difference in growth rates among temperatures, suggesting food limitation. Consumption, respiration, and nitrogen excretion increased with temperature independent of food availability. Lower growth rates coincided with lower phosphorus excretion at the highest temperature, suggesting that fish selectively retained phosphorus at high temperatures and low food. In habitat choice experiments, fish were more likely to use the 12°C side of the tank, closely matching their optimal temperature. We predicted a 9% increase in consumption is required to maintain observed growth under a 4°C warming scenario.These results highlight considering changes in food resources and other associated indirect effects (e.g. excretion) that accompany changing temperatures with climate change. Depending on how food webs respond to warming, fish may cope with predicted warming if density‐dependent feedback maintains population sizes. [ABSTRACT FROM AUTHOR]

Introduction: In November 2016, our institution switched from alfentanil to fentanyl for analgesia and sedation in adult patients receiving extracorporeal membrane oxygenation. There is no published evidence comparing the use of alfentanil with fentanyl for sedation in extracorporeal membrane oxygenation patients. We conducted a retrospective observational study to explore any significant differences in patient outcomes or in the prescribing of adjunct sedatives before and after the switch. Methods: Patients were retrospectively identified from a prospectively recorded database of all patients who received extracorporeal membrane oxygenation at our institution between January 2016 and October 2017. Patients included those sedated with alfentanil or fentanyl. The total daily doses of intravenous opioids (alfentanil or fentanyl) were calculated for each patient, and the prescribing of adjunctive sedative or analgesic agents was recorded. Patient demographics, extracorporeal membrane oxygenation modality, clinical outcomes including mortality and length of intensive care and hospital stay were recorded. Results: A total of 174 patients were identified, 69 on alfentanil and 95 on fentanyl. There was no difference found between groups for mode of extracorporeal membrane oxygenation, age, Acute Physiology and Chronic Health Evaluation 2 score (APACHE II) and Charlson score, except for body mass index (p = 0.002). No differences in patient outcomes was observed between groups, although patients in the alfentanil group received a significantly higher median total daily dose of adjuvant sedatives (quetiapine (p = 0.016) and midazolam (p = 0.009)). Conclusions: No differences in patient outcomes were found between extracorporeal membrane oxygenation patients sedated with alfentanil compared with fentanyl. There was a statistically significant reduction in some adjunctive sedatives in patients managed with a fentanyl-based regimen. Prospective studies are required to confirm these results. [ABSTRACT FROM AUTHOR]

We improved lake mixing process simulations by applying a vertical mixing scheme, K profile parameterization (KPP), in the Community Land Model (CLM) version 4.5, developed by the National Center for Atmospheric Research. Vertical mixing of the lake water column can significantly affect heat transfer and vertical temperature profiles. However, the current vertical mixing scheme in CLM assumes that mixing is driven primarily by wind, and it produces large biases in thermal process simulations. We improved the CLM lake model by using KPP, where vertical mixing was driven by winds and surface thermal forcing, the latter representing the net heat flux in the lake boundary layer. We chose an Arctic Alaskan lake to evaluate this improved lake model. Results demonstrated that KPP could reproduce the observed lake mixing and significantly improved lake temperature simulations when compared to the original mixing scheme in CLM. Our newly improved model better represents the transition between stratification and turnover due to surface thermal forcing combined with high winds. This improved lake model has great potential for reliable physical lake process predictions and better ecosystem services. [ABSTRACT FROM AUTHOR]

Functional oxides displaying phenomena such as 2D electron gas (2DEG) at oxide interfaces represent potential technological breakthroughs for post‐CMOS (Complementary Metal Oxide Semiconductor) electronics. Noninvasive techniques are required to study the surface chemistry and electronic structure underlying their often unique electrical properties. The sensitivity of photoemission electron microscopy (PEEM) to local potential, chemistry, and electronic structure makes it an invaluable tool for probing the near surface region of microscopic regions and domains of functional materials. In particular, PEEM allows single shot acquisition of the 2D Fermi surface and full angular probing of the symmetry‐induced intensity modulations. We present results demonstrating a 2DEG at the surface of SrTiO3(001) at 140 K. The 2DEG is created by soft X‐ray irradiation and can be reversibly controlled by a combination of soft X‐rays and oxygen partial pressure. [ABSTRACT FROM AUTHOR]

Background Training procedural skills using proficiencybased progression (PBP) methodology has consistently resulted in error reduction. We hypothesised that implementation of metric-based PBP training and a valid assessment tool would decrease the failure rate of epidural analgesia during labour when compared to standard simulation-based training. Methods Detailed, procedure-specific metrics for labour epidural catheter placement were developed based on carefully elicited expert input. Proficiency was defined using criteria derived from clinical performance of experienced practitioners. A PBP curriculum was developed to train medical personnel on these specific metrics and to eliminate errors in a simulation environment. Seventeen novice anaesthetic trainees were randomly allocated to undergo PBP training (Group P) or simulation only training (Group S). Following training, data from the first 10 labour epidurals performed by each participant were recorded. The primary outcome measure was epidural failure rate. Results A total of 74 metrics were developed and validated. The inter-rater reliability (IRR) of the derived assessment tool was 0.88. Of 17 trainees recruited, eight were randomly allocated to group S and six to group P (three trainees did not complete the study). Data from 140 clinical procedures were collected. The incidence of epidural failure was reduced by 54% with PBP training (28.7% in Group S vs 13.3% in Group P, absolute risk reduction 15.4% with 95% CI 2% to 28.8%, p=0.04). Conclusion Procedure-specific metrics developed for labour epidural catheter placement discriminated the performance of experts and novices with an IRR of 0.88. Proficiency-based progression training resulted in a lower incidence of epidural failure compared to simulation only training. Trial registration number NCT02179879. NCT02185079; Post-results. [ABSTRACT FROM AUTHOR]

The domain structure of uniaxial ferroelectric lithium niobate single crystals is investigated using Raman spectroscopy mapping. The influence of doping with magnesium and poling at room temperature is studied by analysing frequency shifts at domain walls and their variations with dopant concentration and annealing conditions. It is shown that defects are stabilized at domain walls and that changes in the defect structures with Mg concentration can be probed by the shift of Raman modes. We show that the signatures of polar defects in the bulk and at the domain walls differ. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]