1,598 research outputs found

    Effect of doping and oxygen vacancies on the octahedral tilt transitions in the BaCeO3 perovskite

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    We present a systematic study of the effect of Y doping and hydration level on the structural transformations of BaCeO3 based on anelastic spectroscopy experiments. The temperature of the intermediate transformation between rhombohedral and orthorhombic Imma phases rises with increasing the molar fraction x of Y roughly as (500 K)x in the hydrated state, and is depressed of more than twice that amount after complete dehydration. This is explained in terms of the effect of doping on the average (Ce/Y)-O and Ba-O bond lengths, and of lattice relaxation from O vacancies. The different behavior of the transition to the lower temperature Pnma orthorhombic phase is tentatively explained in terms of progressive flattening of the effective shape of the OH ion and ordering of the O vacancies during cooling.Comment: 8 pages, 5 figure

    The role of weighing-bathing sequence and postmenstrual age in eliciting adaptive/maladaptive responses in very low birth weight preterm infants

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    Purpose: In the neonatal intensive care unit, preterm infants are exposed to several stressful stimuli. Inappropriate stimulation led to high risk for short- and long-term neurocognitive disabilities. This study aimed to evaluate whether the sequence of execution of weighing/bathing nursing procedures and postmenstrual age (PMA) have any effect on preterm infants' stress responses. Design and Methods: Prospective cross-sectional study on a sample of 21 preterm infants. Responses to the procedures were assessed using an observational sheet based on Als's Synactive Theory of Development. Autonomic and motor responses were scored according to five-point Likert scales. The order of execution of weighing/bathing nursing procedures and PMA were documented. Effects of weighing/bathing execution sequence and PMA on autonomic and motor response scores were analyzed by linear multiple regression analysis. Results: The sequence of execution had a significant effect on the autonomic score during weighing (p =.035), evidencing more stress when weighing was executed first. A higher level of stress response on the autonomic score during both weighing (p =.015) and bathing (p =.018) procedure was independently associated with a lower infant PMA. Conclusions and Practice Implications: The real-time recognition of adaptive/maladaptive responses allows nurses to personalize their approach to preterm infants, taking into account PMA and adjusting the appropriate sequence of execution of weighing/bathing nursing procedures

    The role of parental alcohol use, parental discipline and antisocial behaviour on adolescent drinking trajectories

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    Backgrounds: : Parental drinking, harsh parental discipline and adolescent antisocial behaviour have been independently implicated in adolescent alcohol use. Robust prospective studies are required to examine developmental relationships between these factors and their effect on trajectories of alcohol use across adolescence

    Responsive Pickering Emulsions Stabilized by Frozen Complex Coacervate Core Micelles

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    [Image: see text] Frozen complex coacervate core micelles (C3Ms) were developed as a class of particle stabilizers for Pickering emulsions. The C3Ms are composed of a core of electrostatically interacting weak polyelectrolytes, poly(acrylic acid) (pAA) and poly(dimethylaminopropylacrylamide) (pDMAPAA), surrounded by a corona of water-soluble and surface active poly(N-isopropylacrylamide) (pNiPAM). Mixing parameters of the two polymer solutions, including pH, mixing method, charge ratio, and salinity of the medium, were carefully controlled, leading to monodisperse, colloidally stable C3Ms. A combination of dynamic light scattering and proton nuclear magnetic resonance experiments showed that the C3Ms gradually disassembled from a dynamically frozen core state in pure water into free polyelectrolyte chains above 0.8 M NaCl. Upon formulation of dodecane-in-water emulsions, the frozen C3Ms adsorb as particles at the droplet interfaces in striking contrast with most of the conventional micelles made of amphiphilic block copolymers which fall apart at the interface. Eventually, increasing the salt concentration of the system triggered disassembly of the C3Ms, which led to emulsion destabilization

    PO-0954 Click! Engaging Children In Research About Their Lives: Experiences Of Using Photo-elicitation From England, Australia And New Zealand

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    Background and aims. Engaging children in research about their lives is an essential component of providing excellent health care services. Utilising participatory, visual/arts-based approaches such as photo-elicitation (PE) can extend opportunities for children to reflect on and talk about their lives. This paper aims to explore the use of, benefits and issues associated with using PE with children. Methods. PE is a participatory, qualitative method that does not rely on high levels of verbal or written literacy and which creates equitable conditions for children’s engagement in research. Within a broad brief, children are asked to take topic-related photos. Apart from safety/privacy related guidance about where it might not be appropriate to take photographs, the children are free to take any image that has meaning to them. The children then select the images they wish to discuss and the researcher literally has to ‘follow’ the children’s data and adopt a flexible approach to the conversational interview. Results. Reflecting on our experience with PE we note how the quality of discussion is enhanced and intriguing and unexpected insights into children’s lives are revealed. What children choose to photograph or omit can create interesting tensions; these and other lessons will be shared along with exemplar photographs and stories. Conclusions. Although PE provides considerable opportunities and benefits, it is challenging research to be part of and requires skilled researchers to ensure children are safe during research engagement and that the data provides a robust depth of insight into their lives

    Giant Negative Thermal Expansion Induced by the Synergistic Effects of Ferroelectrostriction and Spin-Crossover in PbTiO3-Based Perovskites

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    The discovery of unusual negative thermal expansion (NTE) provides the opportunity to control the common but much desired property of thermal expansion, which is valuable not only in scientific interests but also in practical applications. However, most of the available NTE materials are limited to a narrow temperature range, and the NTE effect is generally weakened by means of various modifications. Here, we report an enhanced NTE effect that occurs over a wide temperature range (\alpha V = -5.24 * 10-5 {\deg}C^-1, 25-575 {\deg} C), and this NTE effect is accompanied by an abnormal enhanced tetragonality, a large spontaneous polarization, and a G-type antiferromagnetic ordering in the present perovskite-type ferroelectric of (1-x)PbTiO3-xBiCoO3. Specifically, for the composition of 0.5PbTiO3-0.5BiCoO3, an extensive volumetric contraction of ~4.8 % has been observed near the Curie temperature of 700 {\deg}C, which represents the highest level in PbTiO3-based ferroelectrics. According to our experimental and theoretical results, the giant NTE originates from a synergistic effect of the ferroelectrostriction and spin-crossover of cobalt on the crystal lattice. The actual NTE mechanism is contrasted with previous functional NTE materials, in which the NTE is simply coupled with one ordering such as electronic, magnetic, or ferroelectric ordering. The present study sheds light on the understanding of NTE mechanisms and it attests that NTE could be simultaneouslycoupled with different orderings, which will pave a new way toward the design of large NTE materials.Comment: 30 page

    Prevalence of nursing diagnoses as a measure of nursing complexity in a hospital setting

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    Aims: To describe the prevalence of nursing diagnoses on admission among inpatient units and medical diagnoses and to analyse the relationship of nursing diagnoses to patient characteristics and hospital outcomes. Background: Nursing diagnoses classify patients according to nursing dependency and can be a measure of nursing complexity. Knowledge regarding the prevalence of nursing diagnoses on admission and their relationship with hospital outcomes is lacking. Design: Prospective observational study. Methods: Data were collected for 6 months in 2014 in four inpatient units of an Italian hospital using a nursing information system and the hospital discharge register. Nursing diagnoses with prevalence higher or equal to 20% were considered as \u2018high frequency.\u2019 Nursing diagnoses with statistically significant relationships with either higher mortality or length of stay were considered as \u2018high risk.\u2019 The high-frequency/high-risk category of nursing diagnoses was identified. Results: The sample included 2283 patients. A mean of 4\ub75 nursing diagnoses per patient was identified; this number showed a statistically significant difference among inpatient units and medical diagnoses. Six nursing diagnoses were classified as high frequency/high risk. Nursing diagnoses were not correlated with patient gender and age. A statistically significant perfect linear association (Spearman's correlation coefficient) was observed between the number of nursing diagnoses and both the length of stay and the mortality rate. Conclusion: Nursing complexity, as described by nursing diagnoses, was shown to be associated with length of stay and mortality. These results should be confirmed after considering other variables through multivariate analyses. The concept of high-frequency/high-risk nursing diagnoses should be expanded in further studies

    Interplay between local structure and electronic properties on CuO under pressure

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    The electronic and local structural properties of CuO under pressure have been investigated by means of X-ray absorption spectroscopy (XAS) at Cu K edge and ab-initio calculations, up to 17 GPa. The crystal structure of CuO consists of Cu motifs within CuO4_4 square planar units and two elongated apical Cu-O bonds. The CuO4_4 square planar units are stable in the studied pressure range, with Cu-O distances that are approximately constant up to 5 GPa, and then decrease slightly up to 17 GPa. In contrast, the elongated Cu-O apical distances decrease continuously with pressure in the studied range. An anomalous increase of the mean square relative displacement (EXAFS Debye Waller, \sigma2^2) of the elongated Cu-O path is observed from 5 GPa up to 13 GPa, when a drastic reduction takes place in \sigma2^2. This is interpreted in terms of local dynamic disorder along the apical Cu-O path. At higher pressures (P>13 GPa), the local structure of Cu2+^{2+} changes from a 4-fold square planar to a 4+2 Jahn-Teller distorted octahedral ion. We interpret these results in terms of the tendency of the Cu2+^{2+} ion to form favorable interactions with the apical O atoms. Also, the decrease in Cu-O apical distance caused by compression softens the normal mode associated with the out-of-plane Cu movement. CuO is predicted to have an anomalous rise in permittivity with pressure as well as modest piezoelectricity in the 5-13 GPa pressure range. In addition, the near edge features in our XAS experiment show a discontinuity and a change of tendency at 5 GPa. For P < 5 GPa the evolution of the edge shoulder is ascribed to purely electronic effects which also affect the charge transfer integral. This is linked to a charge migration from the Cu to O, but also to an increase of the energy band gap, which show a change of tendency occurring also at 5 GPa

    A sensitivity analysis of the New Zealand standard model of foot and mouth disease

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    Summary Disease simulation models can be a valuable tool for planning a response to exotic disease incursions, as they provide a fast, low-cost mechanism for identifying the likely outcomes of a range of outbreak scenarios and disease control strategies. To use these tools effectively and with confidence, decisionmakers must understand the simplifications and framing assumptions that underlie a model&apos;s structure. Sensitivity analysis, the analytical process of identifying which input variables are the key drivers of the model&apos;s output, is a crucial process in developing this understanding. This paper describes the application of a sampling-based sensitivity analysis to the New Zealand standard model (NZSM). This model is a parameter set developed for the InterSpread Plus model platform to allow the exploration of different outbreak scenarios for an epidemic of foot and mouth disease in New Zealand. Based on 200 iterations of the NZSM, run for a simulation period of 60 days, settings related to farm-to-saleyard movements and the detection of disease during the active surveillance phase of the epidemic had the greatest influence on the predicted number of infected premises. A small number of counter-intuitive findings indicated areas of model design, implementation and/or parameterisation that should be investigated further. A potentially useful result from this work would be information to aid the grouping or elimination of non-influential model settings. This would go some way towards reducing the overall complexity of the NZSM, while still allowing it to remain fit for purpose

    Disseminating an Evidence-Based Course to Teach Self-Management of Auditory Hallucinations

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    This multi-site project extended course dissemination of the 10-session Behavioral Management of Auditory Hallucinations Course to U.S. Department of Veterans Affairs (VA) mental health outpatient settings. The VA Quality Enhancement Research Initiative (QUERI) model and Rogers\u27 theory of diffusion of innovations served as the theoretical framework. The course was taught to mental health professionals using teleconferencing, electronic media, and monthly conference calls across 24 VA mental health outpatient sites. Twenty course leaders provided feedback. One hundred percent reported being better able to communicate with patients about their voices and 96% reported improved understanding of the voice-hearing experience. Thirty-three course participants provided feedback. Ninety-four percent would recommend the course, 85% reported being better able to communicate with staff about their voices, and 66% reported being better able to manage their voices. Facilitators and barriers to course implementation are described
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