320 research outputs found
Computer simulation of defect clusters in UO2 and their dependence on composition
AbstractIt is recognised that point defects play a key role in the behaviour and properties of many technologically significant oxides. What is less well understood is how these defects cluster together and, crucially, the extent to which the clusters change with composition. We chose to investigate this phenomenon by considering UO2, a nuclear fuel material for which there is contradictory data in the literature concerning defect clustering as a function of oxygen content. Early studies of fluorite UO2+x proposed a model based on 2:2:2 Willis clusters whilst more recent research suggests cuboctahedral or split quad-interstitial defect clustering. Here we use the PBE+U functional to simulate defective UO2+x and find for 0.125<x<0.25, chains of edge-sharing 2:2:2 Willis clusters to be most stable. Below x=0.125 these chains destabilise, transforming in to split di-interstitial clusters, demonstrating that the type of oxygen cluster present is dependent on local environment and stoichiometry
Purified and specific cytoplasmic pollen extract: a non-hormonal alternative for the treatment of menopausal symptoms
Research into non-hormonal, alternative therapies is necessary for women for whom menopausal hormone therapy is contraindicated or for women who do not wish to take hormones. This review focuses on one such non-hormonal option, namely, purified and specific cytoplasmic pollen extract, or PureCyTonin (R). This extract has been evaluated in several preclinical and clinical studies, where it demonstrated its value as a safe and non-estrogenic alternative for menopause. This review presents the beneficial effects of PureCyTonin (R) in the treatment of menopausal symptoms (e.g. hot flushes) in healthy women, as well as in premenstrual syndrome. We discuss the mechanism of action of PureCyTonin (R), an SSRI-'like' therapy. The lack of estrogenic effect demonstrated in preclinical studies suggests that PureCyTonin (R) may also be a suitable option for the management of menopausal symptoms in women with breast cancer
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Defect segregation facilitates oxygen transport at fluorite UO<sub>2</sub> grain boundaries
Data support article accepted for publication in Philosophical Transactions A. Data includes inputs and outputs for molecular dynamics simulations. Where impractical simulations can be rerun from the inputs provided
Phase II study of single-agent bosutinib, a Src/Abl tyrosine kinase inhibitor, in patients with locally advanced or metastatic breast cancer pretreated with chemotherapy
Background: This phase II study evaluated single-agent bosutinib in pretreated patients with locally advanced or metastatic breast cancer. Patients and methods: Patients received oral bosutinib 400 mg/day. The primary end point was the progression-free survival (PFS) rate at 16 weeks. Secondary end points included objective response rate, clinical benefit rate, 2-year overall survival rate, safety, and changes in levels of bone resorption/formation biomarkers. Results: Seventy-three patients were enrolled and treated. Median time from diagnosis of metastatic disease to initiation of bosutinib treatment was 24.5 months. For the intent-to-treat population, the PFS rate at 16 weeks was 39.6%. Unexpectedly, all responding patients (n = 4) were hormone receptor positive. The clinical benefit rate was 27.4%. The 2-year overall survival rate was 26.4%. The main toxic effects were diarrhea (66%), nausea (55%), and vomiting (47%). Grade 3-4 laboratory aminotransferase elevations occurred in 14 (19%) patients. Myelosuppression was minimal. No consistent changes in the levels of bone resorption/formation biomarkers were seen. Conclusions: Bosutinib showed promising efficacy in prolonging time to progression in chemotherapy-pretreated patients with locally advanced or metastatic breast cancer. Bosutinib was generally well tolerated, with a safety profile different from that of the Src/Abl tyrosine kinase inhibitor dasatinib in a similar patient population.peer-reviewe
Curriculum Theory, Didaktik, and Educational Leadership: Reflections on the Foundations of the Research Program
This chapter provides concluding reflections and next steps in a research program bridging curriculum theory/Didaktik and educational leadership studies. The bridging utilizes non-affirmative education theory as the theoretical ground. To begin, we present a retrospective discussion of the project. We then relate the approach to the contributions included in this volume, especially focusing on the normativity of education theories, and pointing at how non-affirmative education theory corresponds to deliberation oriented democratic-hermeneutic initiatives. Non-affirmative education theory identifies both leadership, teaching and curriculum work as critical deliberation based professional activities driven by subjects, individual agency in historically developed cultural and societal institutions framed by policies. Non-affirmative educational leadership practices are expected to take a critical stand regarding given policies, and other expectations, yet mindful of that education in democratic societies, typically following a Bildung tradition aim at individuals making up of their own minds and learning that practices, also moral and political ones, may and can be changed. The approach applied in this volume, i.e. to point at the roots of modern European education theory not only helps us to better see connections between this Bildung tradition, Deweyan pragmatism and deliberative democracy but is also used as a point of departure to continue towards comparative research on how educational leadership work is carried out in the intersection between curriculum as a policy document and leadership practices at different levels as discursive practices
The disappearance and reappearance of optical emission lines and the drop in a Swift/XRT count rate during the recent rebrightening of TCP J21040470+4631129
We report the results of our continuing optical and X-ray monitoring of the bright WZ Sge-type dwarf
nova TCP J21040470+4631129 (hereafter TCP2104) discovered on July 12, 2019 (for previous reports,
see ATel #12947, #13009). Our optical photometric observations are mostly performed using 30-cm class
telescopes, while spectroscopic data are obtained with the 2.1-m telescope at the OAN-SPM, the 2.5-m
Isaac Newton Telescope on La Palma, and other smaller telescopes.peer-reviewe
Recurrent Connections Aid Occluded Object Recognition by Discounting Occluders
Recurrent connections in the visual cortex are thought to aid object
recognition when part of the stimulus is occluded. Here we investigate if and
how recurrent connections in artificial neural networks similarly aid object
recognition. We systematically test and compare architectures comprised of
bottom-up (B), lateral (L) and top-down (T) connections. Performance is
evaluated on a novel stereoscopic occluded object recognition dataset. The task
consists of recognizing one target digit occluded by multiple occluder digits
in a pseudo-3D environment. We find that recurrent models perform significantly
better than their feedforward counterparts, which were matched in parametric
complexity. Furthermore, we analyze how the network's representation of the
stimuli evolves over time due to recurrent connections. We show that the
recurrent connections tend to move the network's representation of an occluded
digit towards its un-occluded version. Our results suggest that both the brain
and artificial neural networks can exploit recurrent connectivity to aid
occluded object recognition.Comment: 13 pages, 5 figures, accepted at the 28th International Conference on
Artificial Neural Networks, published in Springer Lecture Notes in Computer
Science vol 1172
A one-stop perineal clinic: our eleven-year experience.
INTRODUCTION AND HYPOTHESIS: The perineal clinic is a dedicated setting offering assessment for various childbirth-related presentations including obstetric anal sphincter injuries (OASIs), perineal wound complications, pelvic floor dysfunction and other conditions such as female genital mutilation(FGM). We describe the clinical presentation and outcomes of women from a tertiary perineal clinic based on data collected over an 11-year period. METHODS: This is a retrospective observational study. A one-stop outpatient service was offered to all women who sustained OASIs (postnatally and antenatally in a subsequent pregnancy), perineal complications (within 16Â weeks postpartum), FGM and/or peripartum symptoms of urinary/anal incontinence or prolapse. Assessment included history with validated questionnaires, examination and anal manometry and endoanal ultrasound when appropriate. Outcomes were compared among different grades of OASIs. Management of each type of presentation was reported with outcomes. RESULTS: There were 3254 first attendance episodes between 2006 and 2016. The majority (58.1%) were for OASIs, followed by perineal wound complications. Compared to the lower grades, the higher grades of OASI were associated with poorer outcomes in terms of symptoms, investigations and complications. Women with OASIs had unrelated symptoms such as urinary incontinence, perineal pain and wound infections that needed further intervention. A high proportion(42%) of wound complications required further specialist management. CONCLUSION: We describe a dedicated, one-stop perineal clinic model for antenatal and postnatal women for management of perineal and pelvic floor disorders. This comprehensive and novel data will enable clinicians to better counsel women regarding of outcomes after OASI and focus training to minimize risks of morbidities
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