Controlling surface cation segregation in a double perovskite for oxygen anion transport in high temperature energy conversion devices.

Double perovskite materials have shown promising applications as an electrode in solid oxide fuel cells and Li-air batteries for oxygen reduction, evolution, and transport. However, degradation of the material due to cation migration to the surface, forming secondary phases, poses an existential bottleneck in materials development. Herein, a theoretical approach combining density functional theory and molecular dynamics simulations is presented to study the Ba-cation segregation in a double perovskite NdBaCo2O5+δ. Solutions to circumvent segregation at the molecular level are presented in two different forms by applying strain and introducing dopants in the structure. On applying compressive strain or Ca as a dopant in the NBCO structure, segregation is estimated to reduce significantly. A more direct way of estimating cation segregation is proposed in MD simulations, wherein the counting of the cations migrating from the sub-surface layers to the surface provided a reliable theoretical assessment of the level of cation segregation.

The role of psychological flexibility, perceived injustice and body image in Vulvodynia: A longitudinal study.

BACKGROUND: Women with Vulvodynia experience pain, related impacts on sex and daily functioning, and depression. While psychosocial factors are associated with outcomes in Vulvodynia, longitudinal data are limited, especially in mixed/spontaneous Vulvodynia. Broad psychological models such as psychological flexibility (PF) and content-specific factors, such as body-exposure anxiety (BEA) and avoidance during sexual activities and perceived injustice, have not been adequately investigated in Vulvodynia. The aim of this study was to explore whether these factors assessed at baseline predict pain severity, pain interference, sexual functioning and satisfaction and depression 3 months later. METHODS: A longitudinal study of 349 women with Vulvodynia was conducted. Participants completed online self-report measures of pain-related and sexual outcomes, depression, BEA, perceived injustice and facets of PF (present moment awareness, pain acceptance, committed action) at baseline and after 3 months, overlapping with the Coronavirus disease 2019 (COVID-19) pandemic. RESULTS: Seventy percent of women responded at both assessments (n = 244). There were significant decreases in pain severity, pain interference, present moment awareness, committed action and a significant increase in depression at 3 months. All the baseline psychosocial factors significantly correlated with at least one outcome at 3 months. When adjusting for baseline outcome and demographics, committed action significantly positively predicted depression at 3 months and pain acceptance significantly positively predicted pain interference at 3 months. CONCLUSIONS: Among women with Vulvodynia, pain acceptance and committed action are prospectively associated with pain interference and depression. The reliability and generalizability of these results needs to be established given the overlap with the COVID-19 pandemic. Future studies should investigate whether targeting these factors enhances outcomes in Vulvodynia. SIGNIFICANCE: This longitudinal study explored the role of PF, perceived injustice and body image during sexual activities in predicting pain severity, pain interference, sexual functioning, sexual satisfaction and depression in women with Vulvodynia. The study findings reveal that two facets of PF (committed action and pain acceptance) predicted pain interference and depression over time. It may be important to incorporate these processes in treatments developed for Vulvodynia.

A Network Analysis of Selected Psychosocial Factors in Vulvodynia and Its Subtypes.

OBJECTIVE: Psychosocial factors are related to pain and sex-related outcomes in provoked vulvodynia and possibly in mixed and spontaneous vulvodynia. However, a broader behavioral framework, such as the psychological flexibility model, has received limited attention in this context. Recently, additional psychosocial variables have also emerged that appear relevant to vulvodynia, including perceived injustice, body-exposure anxiety during intercourse, and unmitigated sexual communion. The present study applied network analysis to explore relations between psychological flexibility, newly emerging psychosocial variables relevant to vulvodynia, and their associations with vulvodynia outcomes. The study also explored potential differences across vulvodynia subtypes. DESIGN: An online cross-sectional study of 349 participants with vulvodynia (112 provoked, 237 spontaneous/mixed) was carried out. METHODS: Participants completed self-report questionnaires, including questions on pain and sexual outcomes, depression, facets of psychological flexibility, body-exposure anxiety during intercourse, unmitigated sexual communion, and perceived injustice. Networks were computed for the total sample and for provoked and mixed/spontaneous vulvodynia subsamples. RESULTS: Perceived injustice, pain acceptance, and depression were "central" factors among the included variables, in all models. Psychological flexibility processes were relevant for all networks. Depression was more central in the network for mixed/spontaneous vulvodynia; body-exposure anxiety during intercourse was most central for the provoked subtype. CONCLUSIONS: Among the included variables, perceived injustice, pain acceptance, depression, and psychological flexibility appear to be important in vulvodynia. As different factors are significant across subtypes, tailored treatment approaches are suggested.

Psychosocial factors associated with pain and sexual function in women with Vulvodynia: A systematic review.

BACKGROUND AND OBJECTIVE: Vulvodynia is a prevalent chronic vulval pain condition affecting 10%-28% of women, and significantly impacting their health and quality of life. It is currently poorly understood and biomedical treatments achieve only modest benefits for pain and sexual functioning. A wider psychosocial conceptualization of this condition may improve outcomes. There is currently no coherent understanding of how psychosocial factors may contribute to outcomes in Vulvodynia. The aim of this review is to identify and systematically review psychosocial factors associated with pain and sexual outcomes and to inform a psychosocial model of Vulvodynia. DATABASES AND DATA TREATMENT: Observational/experimental studies reporting on the association between psychosocial factors and pain/sexual outcomes in adult women with Vulvodynia were eligible. Two reviewers independently conducted eligibility screening, data extraction and quality assessment. Twenty-one studies were included, all focused on women with Provoked Vestibulodynia (PVD). Most of the studies were low-to-medium quality. RESULTS/CONCLUSION: A range of general/pain-related distress and avoidance processes, and sex/intimacy avoidance or engagement processes were significantly associated with pain, sexual functioning or sexual distress and sexual satisfaction, supporting the role of a psychosocial approach to PVD. Depression, anxiety, catastrophizing, pain-anxiety, pain acceptance, body-exposure anxiety, attention to sexual cues, partner hostility and solicitousness, self-efficacy and penetration cognitions are highlighted as potentially important treatment targets in PVD. Due to the limited data available, developing a psychosocial model was not possible. Directions for future research include examining the replicability and generalizability of the factors identified, exploring differences/similarities across Vulvodynia subsets and testing tailored theoretically based treatments. SIGNIFICANCE: The systematic review highlights the role of psychosocial factors associated with pain and sexual functioning in Vulvodynia. The review findings reveal that Vulvodynia presents both similar and unique cognitive, behavioural and interpersonal features compared to other chronic pain conditions. There may be important roles for negative sexual cues, body image-related factors during intercourse, partner factors, self-efficacy beliefs and penetration cognitions, in relation to pain and sexual functioning.

Burkholderia Cepacia Complex Causing Pneumonia in an Immunocompetent Non-Cystic Fibrosis Patient: Case Report and Review of Literature.

BACKGROUND: Burkholderia cepacia complex is widespread in the environment and has been recognized as a cause of opportunistic pulmonary infections, particularly in patients with Cystic Fibrosis (CF). The natural ecology of the bacteria as part of plant growth-promoting rhizosphere provides stark contrast to its infectious potential. Its preponderance as a nosocomial pathogen may be due to its ability to survive in antiseptic solutions, contaminate equipments and intrinsic antimicrobial resistance. CASE: An elderly, diabetic male was evaluated for hemoptysis, fever and cough. Chest computed tomography showed a thick walled cavity in the left lung and hilar lymphadenopathy. Sputum examination showed Gram negative bacilli and no acid fast bacilli. Sputum culture yielded growth of non-fermentative Gram negative bacilli on two occasions, but blood culture was sterile. The isolate was identified as B. cepacia by Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). The patient's general condition remained poor and in spite of initiation of antibiotics, the patient expired after an episode of massive hemoptysis. CONCLUSION: This report raises concerns regarding the spread and severity of B. cepacia infection in non-compromised patients in the community and the need to suspect and identify it. Since the organism is inherently resistant to antipseudomonal penicillins, aminoglycosides and polymyxin B, differentiation from Pseudomonas spp. and determining antimicrobial susceptibility is paramount for treatment.

Accumulation patterns of endogenous ß-aminobutyric acid during plant development and defence in Arabidopsis thaliana.

We recently discovered that ß-aminobutyric acid (BABA), a molecule known for its ability to prime defences in plants, is a natural plant metabolite. However, the role played by endogenous BABA in plants is currently unknown. In this study we investigated the systemic accumulation of BABA during pathogen infection, levels of BABA during plant growth and development and analysed mutants possibly involved in BABA transport or regulation. BABA was quantified by LC-MS using an improved method adapted from a previously published protocol. Systemic accumulation of BABA was determined by analysing non-infected leaves and roots after localised infections with Plectosphaerella cucumerina or Pseudomonas syringae pv. tomato (Pst) DC3000 avrRpt2. The levels of BABA were also quantified in different plant tissues and organs during normal plant growth, and in leaves during senescence. Mutants affecting amino acid transport (aap6, aap3, prot1 and gat1), γ-aminobutyric acid levels (pop2) and senescence/defence (cpr5-2) were analysed. BABA was found to accumulate only locally after bacterial or fungal infection, with no detectable increase in non-infected systemic plant parts. In leaves, BABA content increased during natural and induced senescence. Reproductive organs had the highest levels of BABA, and the mutant cpr5-2 produced constitutively high levels of BABA. Synthetic BABA is highly mobile in the receiving plant, whereas endogenous BABA appears to be produced and accumulated locally in a tissue-specific way. We discuss a possible role for BABA in age-related resistance and propose a comprehensive model for endogenous and synthetic BABA.

RSTensorFlow: GPU Enabled TensorFlow for Deep Learning on Commodity Android Devices.

Mobile devices have become an essential part of our daily lives. By virtue of both their increasing computing power and the recent progress made in AI, mobile devices evolved to act as intelligent assistants in many tasks rather than a mere way of making phone calls. However, popular and commonly used tools and frameworks for machine intelligence are still lacking the ability to make proper use of the available heterogeneous computing resources on mobile devices. In this paper, we study the benefits of utilizing the heterogeneous (CPU and GPU) computing resources available on commodity android devices while running deep learning models. We leveraged the heterogeneous computing framework RenderScript to accelerate the execution of deep learning models on commodity Android devices. Our system is implemented as an extension to the popular open-source framework TensorFlow. By integrating our acceleration framework tightly into TensorFlow, machine learning engineers can now easily make benefit of the heterogeneous computing resources on mobile devices without the need of any extra tools. We evaluate our system on different android phones models to study the trade-offs of running different neural network operations on the GPU. We also compare the performance of running different models architectures such as convolutional and recurrent neural networks on CPU only vs using heterogeneous computing resources. Our result shows that although GPUs on the phones are capable of offering substantial performance gain in matrix multiplication on mobile devices. Therefore, models that involve multiplication of large matrices can run much faster (approx. 3 times faster in our experiments) due to GPU support.

Emergence of ferroelectricity in antiferroelectric nanostructures.

First-principles-based finite-temperature simulations are used to predict the emergence of ferroelectricity in antiferroelectric nanostructures made of PbZrO3. The phenomenon is expected to occur in antiferroelectric nanodots, nanowires, and thin films with good surface charge compensation and can be explained by the recently proposed surface effect. Our computations provide a microscopic insight into the equilibrium phases, phase competition, and electrical properties of PbZrO3 nanostructures. The dependence of these properties on the electrical boundary conditions and nanostructure size is investigated.

Publisher's Note: Critical Thickness for Antiferroelectricity in PbZrO_{3} [Phys. Rev. Lett. 115, 097601 (2015)].

This corrects the article DOI: 10.1103/PhysRevLett.115.097601.

Publisher's Note: Thermally Mediated Mechanism to Enhance Magnetoelectric Coupling in Multiferroics [Phys. Rev. Lett. 114, 177205 (2015)].

This corrects the article DOI: 10.1103/PhysRevLett.114.177205.

Scaling law for electrocaloric temperature change in antiferroelectrics.

A combination of theoretical and first-principles computational methods, along with experimental evidence from the literature, were used to predict the existence of a scaling law for the electrocaloric temperature change in antiferroelectric materials. We show that the temperature change scales quadratically with electric field, allowing a simple transformation to collapse the set of ΔT(E) onto a single curve. This offers a unique method that can be used to predict electrocaloric behavior beyond the limits of present measurement ranges or in regions where data are not yet available.

Electrocaloric effect in ferroelectric nanowires from atomistic simulations.

Electrocaloric effect is presently under active investigation owing to both the recent discoveries of giant electrocaloric effects and its potential for solid state cooling applications. We use first-principles-based direct simulations to predict the electrocaloric temperature change in ferroelectric ultrathin nanowires. Our findings suggest that in nanowires with axial polarization direction the maximum electrocaloric response is reduced when compared to bulk, while the room temperature electrocaloric properties can be enhanced by tuning the ferroelectric transition temperature. The potential of ferroelectric nanowires for electrocaloric cooling applications is discussed.