382 research outputs found

    Observation of surface states on heavily indium doped SnTe(111), a superconducting topological crystalline insulator

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    The topological crystalline insulator tin telluride is known to host superconductivity when doped with indium (Sn1x_{1-x}Inx_{x}Te), and for low indium contents (x=0.04x=0.04) it is known that the topological surface states are preserved. Here we present the growth, characterization and angle resolved photoemission spectroscopy analysis of samples with much heavier In doping (up to x0.4x\approx0.4), a regime where the superconducting temperature is increased nearly fourfold. We demonstrate that despite strong p-type doping, Dirac-like surface states persist

    Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions

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    In this work, the hydrogen evolution reaction (HER) was studied on Ru coated Ti2AlC electrodes in 1.0 mol dm(-3) H2SO4 at 25 degrees C. Ti2AlC was found to be a highly stable substrate in sulfuric acid solutions due to the formation of a passivating oxide layer on the surface, which was confirmed by the X-ray photoelectron spectroscopy (XPS) analysis of as-prepared and anodically treated Ti2AlC samples. Ru films were electrodeposited onto Ti2AlC substrates by cycling the potential of Ti2AlC in the solution containing 0.01 mol dm(-3) RuCl3 + 0.1 mol dm(-3) H2SO4 between -0.5 V and 0.4 V vs. a saturated calomel electrode (SCE) at the sweep rate of 20 mV s(-1). Four Ru/Ti2AlC samples were prepared, obtained at 5, 10, 15 and 20 cycles of Ru electrodeposition. Characterization of samples was performed by scanning electron microscopy (SEM) and cyclic voltammetry (CV), while the thickness of the electrodeposited Ru layers was determined by atomic force microscopy (AFM). It was found that the most compact sample with the thickness of about 0.42 mu m was obtained after 5 cycles. Electrochemical impedance spectroscopy (EIS) and steady-state polarization measurements showed that all Ru/Ti2AlC electrodes were exceptionally active for the HER. A Tafel slope of about -60 mV dec(-1) was observed on all polarization curves in the range of high cathodic current densities. Based on formal kinetics analysis, an appropriate mechanism for the HER on Ru/Ti2AlC was suggested.This is the peer-reviewed version of the article: Jovic, B. M., Jović, V. D., Lačnjevac, U., Stevanović, S., Kovac, J., Radovic, M.,& Krstajić, N. V. (2016). Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions. Journal of Electroanalytical Chemistry, Elsevier, 766, 78-86. [https://doi.org/10.1016/j.jelechem.2016.01.038]The published version: [https://cer.ihtm.bg.ac.rs/handle/123456789/2012

    The psychosocial impact of microtia and ear reconstruction: A national data-linkage study

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    IntroductionChildren with visible facial differences are believed to be at increased risk of negative psychosocial behaviours which may manifest as affective disorders. The aim of this study was to determine whether a diagnosis of microtia, and the associated surgical intervention, is associated with psychosocial implications including impaired educational attainment and a diagnosis of an affective disorder.MethodsA retrospective case-control study was conducted using data linkage to identify patients in Wales with a diagnosis of microtia. Matched controls were sought on the basis of age, gender and socioeconomic deprivation status to yield a total sample size of 709. incidence was calculated using annual and geographic birth rates. Surgical operation codes were used to classify patients into those that had no surgery, autologous reconstruction or prosthetic reconstruction. Educational attainment at 11 years of age, plus a diagnosis of depression or anxiety were used as markers of adverse psychosocial outcomes and the relative risk was attained using logistic regression analyses.ResultsThere were no significant associations between a diagnosis of microtia and an increased risk of adverse educational attainment or a risk of an affective disorder diagnosis. Male gender and higher deprivation scores were significantly associated with poorer educational attainment, irrespective of a diagnosis of microtia. Surgical intervention of any nature was also not associated with any increased risk of adverse educational or psychosocial outcomes in microtia patients.DiscussionMicrotia patients in Wales do not appear to be at greater risk of developing affective disorders or impaired academic performance as a result of their diagnosis or associated surgical intervention. Whilst reassuring, the need for appropriate support mechanisms to maintain positive psychosocial wellbeing and academic achievement in this patient cohort is reinforced

    Two-years Postradiotherapy Biopsies: Lessons from MRC RT01 Trial

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    Background: The importance of 2-yr postradiotherapy prostate biopsy status remains uncertain. Objective: To assess the value of 2 year post treatment biopsies in a randomised trial of radiotherapy dose escalation. Design, setting, and participants: Between 1998 and 2001, 843 men with localised prostate cancer were randomised to receive either control-64 Gy or escalated-74 Gy conformal radiotherapy (CFRT) in the MRC RT01 trial in combination with 3–6-mo neoadjuvant androgen deprivation therapy. Prostate biopsies were planned at 2 yr from start of CFRT in suitable men. Outcome measurements and statistical analysis: Prostate biopsy results and prostate-specific antigen (PSA) levels performed at 2 yr post-CFRT were evaluated with long-term biochemical progression free survival (bPFS) and overall survival. Outcome measures were timed from the 2-yr biopsy using a landmark approach. Results and limitations: A 2-yr biopsy was performed in 312/843 patients. One hundred and seventy-seven patients were included in the per-protocol group with median follow-up of 7.8 yr from biopsy. Median PSA at biopsy was 0.5 ng/ml. Sixty-four bPFS events were reported: 46/145 (32%) in patients with negative, 6/18 (33%) suspicious, and 12/14 (86%) positive biopsies. A positive biopsy was prognostic of worse bPFS, going forward, compared with negative and suspicious biopsies, hazard ratio (HR) = 4.81 (95% confidence interval [CI]: 2.50–9.26, p < 0.001). The estimate for survival was HR = 1.58 (95% CI: 0.52–4.78, p = 0.42). PSA values at 2 yr between 1.01 ng/ml and 2.09 ng/ml were also associated with subsequent PSA failures (HR = 2.71, 95% CI: 1.98–3.71), bPFS events (HR = 2.45, 95% CI: 1.81–3.32), and prostate cancer-specific survival (HR = 2.87, 95% CI: 1.08–7.64) compared with PSA ≤1.0 ng/ml. Conclusions: Two-year postradiotherapy prostate biopsies have limited value in patients with PSA control but both positive biopsy and higher PSA status are strongly associated with future bPFS events. A policy of selected biopsy may provide an opportunity for early salvage interventions. Patient summary: Routine 2-yr postradiotherapy biopsy is not recommended but can be considered in selected patients with unfavourable post-treatment prostate-specific antigen levels who are suitable for early salvage treatments

    Soliton formation by decelerating interacting Airy beams

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    We demonstrate a new type of soliton formation arising from the interaction of multiple two-dimensional Airy beams in a nonlinear medium. While in linear regime, interference effects of two or four spatially displaced Airy beams lead to accelerated intensity structures that can be used for optical induction of novel light guiding refractive index structures, the nonlinear cross-interaction between the Airy beams decelerates their bending and enables the formation of straight propagating solitary states. Our experimental results represent an intriguing combination of two fundamental effects, accelerated optical beams and nonlinearity, together enable novel mechanisms of soliton formation that will find applications in all-optical light localization and switching architectures. Our experimental results are supported by corresponding numerical simulations

    Light localization in optically induced deterministic aperiodic Fibonacci lattices

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    As light localization becomes increasingly pronounced in photonic systems with less order, we investigate optically induced two-dimensional Fibonacci structures that are supposed to be among the most ordered realizations of deterministic aperiodic patterns. For the generation of corresponding refractive index structures, we implement a recently developed incremental induction method using nondiffracting Bessel beams as waveguide formation entities. Even though Fibonacci structures present slightly reduced order, we show that transverse light transport here is significantly hampered in comparison with discrete diffraction in a periodic lattice. Numerical simulations that support our experimental findings help to identify three cases of input waveguide configurations that significantly determine the initial propagation in a Fibonacci structure. These crucial starting conditions determine the character of light transport, yielding either localization or enhanced expansion. A diverse set of light transport scenarios is identified therein

    Sem/Edx and Xrd Characterization of Silver Nanocrystalline Thin Film Prepared from Organometallic Solution Precursor

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    The Ag nano-structured thin films prepared on flat glass substrates have been studied. The ball-like silver nanoparticles have been synthesized in large quantity by using a modified method of hydrolytic decomposition of silver complexes with amino types ligands formed in ethanol aqueous solution. SEM analysis revealed that Ag nanoparticles are all sphere shaped with bimodal size (40 and 70 nm) distribution. The results of XRD powder pattern examination show that Ag nanoparticles are pure phase, well crystallized. The unit cell dimensions measured on synthesized Ag nano films show small but frequent contraction in comparison to Ag metal standard

    Health literacy, health status, and healthcare utilization of Taiwanese adults: results from a national survey

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    Abstract Background Low health literacy is considered a worldwide health threat. The purpose of this study is to assess the prevalence and socio-demographic covariates of low health literacy in Taiwanese adults and to investigate the relationships between health literacy and health status and health care utilization. Methods A national survey of 1493 adults was conducted in 2008. Health literacy was measured using the Mandarin Health Literacy Scale. Health status was measured based on self-rated physical and mental health. Health care utilization was measured based on self-reported outpatient clinic visits, emergency room visits, and hospitalizations. Results Approximately thirty percent of adults were found to have low (inadequate or marginal) health literacy. They tended to be older, have fewer years of schooling, lower household income, and reside in less populated areas. Inadequate health literacy was associated with poorer mental health (OR, 0.57; 95% CI, 0.35-0.91). No association was found between health literacy and health care utilization even after adjusting for other covariates. Conclusions Low (inadequate and marginal) health literacy is prevalent in Taiwan. High prevalence of low health literacy is not necessarily indicative of the need for interventions. Systematic efforts to evaluate the impact of low health literacy on health outcomes in other countries would help to illuminate features of health care delivery and financing systems that may mitigate the adverse health effects of low health literacy.http://deepblue.lib.umich.edu/bitstream/2027.42/78252/1/1471-2458-10-614.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78252/2/1471-2458-10-614.pdfPeer Reviewe
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