7,640 research outputs found

    Enhancement of bulk second-harmonic generation from silicon nitride films by material composition

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    We present a comprehensive tensorial characterization of second-harmonic generation from silicon nitride films with varying composition. The samples were fabricated using plasma-enhanced chemical vapor deposition, and the material composition was varied by the reactive gas mixture in the process. We found a six-fold enhancement between the lowest and highest second-order susceptibility, with the highest value of approximately 5 pm/V from the most silicon-rich sample. Moreover, the optical losses were found to be sufficiently small (below 6 dB/cm) for applications. The tensorial results show that all samples retain in-plane isotropy independent of silicon content, highlighting the controllability of the fabrication process.Comment: 4 pages, 3 figures, 2 tables; Re-submitted to Optics Letter

    Comparative study of efficacy and safety of intravenous ferric carboxy maltose versus iron sucrose in treatment of postpartum iron deficiency anemia

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    Background: As postpartum iron deficiency anemia is observed in about 65% of women in India, it is the major contributing factor and indirect cause of maternal death. Postpartum anemia may lead to postpartum depression, stress, anxiety and cognitive impairment. Adequate treatment of anemia in postpartum period will have improved life quality in women in child bearing age so this study was designed with the objective to compare the safety and efficacy of intravenous FCM versus iron sucrose in treatment of postpartum iron deficiency anemia.Methods: It was a prospective observational study of postpartum women (within 10 days of delivery) with iron deficiency anemia (7-9 gm%) who delivered in LG hospital, Ahmedabad. A sample size of 215 women was estimated based on prevalence of anemia which is 65% among postpartum women in India including dropout rate of 10% which were further divided into 2 groups. Group 1: iron sucrose group, Group 2: ferric carboxy maltose group.Results: FCM has greater rise in Hb, less side effects, and easy administration of dose as compared to iron sucrose. The rise in Hb with FCM as compared to iron sucrose is (4.6 versus 3.5 respectively).Conclusions: FCM has more safety and efficacy as compared to iron sucrose in treatment of postpartum iron deficiency anemia

    Deep Learning using K-space Based Data Augmentation for Automated Cardiac MR Motion Artefact Detection

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    Quality assessment of medical images is essential for complete automation of image processing pipelines. For large population studies such as the UK Biobank, artefacts such as those caused by heart motion are problematic and manual identification is tedious and time-consuming. Therefore, there is an urgent need for automatic image quality assessment techniques. In this paper, we propose a method to automatically detect the presence of motion-related artefacts in cardiac magnetic resonance (CMR) images. As this is a highly imbalanced classification problem (due to the high number of good quality images compared to the low number of images with motion artefacts), we propose a novel k-space based training data augmentation approach in order to address this problem. Our method is based on 3D spatio-temporal Convolutional Neural Networks, and is able to detect 2D+time short axis images with motion artefacts in less than 1ms. We test our algorithm on a subset of the UK Biobank dataset consisting of 3465 CMR images and achieve not only high accuracy in detection of motion artefacts, but also high precision and recall. We compare our approach to a range of state-of-the-art quality assessment methods.Comment: Accepted for MICCAI2018 Conferenc

    Time-Accurate Numerical Simulations of Synthetic Jet Quiescent Air

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    The unsteady evolution of three-dimensional synthetic jet into quiescent air is studied by time-accurate numerical simulations using a second-order accurate mixed explicit-implicit fractional step scheme on Cartesian grids. Both two-dimensional and three-dimensional calculations of synthetic jet are carried out at a Reynolds number (based on average velocity during the discharge phase of the cycle V(sub j), and jet width d) of 750 and Stokes number of 17.02. The results obtained are assessed against PIV and hotwire measurements provided for the NASA LaRC workshop on CFD validation of synthetic jets

    Kinetics and spectral properties of electron and <SUP>&#8226;</SUP>OH adducts of dimethylpyridines: a pulse radiolysis study

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    The reactions of e-aq, &#8226;OH&#8226;-, O&#8226;- and SO&#8226;-4 with 2,4-, 2,6- and 3,5-dimethylpyridines have been investigated in aqueous solution by pulse radiolysis with optical detection. Both e-aq and &#8226;OH radicals have high reactivity toward these compounds with k = 4-8&#215;109 dm3 mol-1 s-1. The rates of O&#8226; and SO&#8226;-4 reactions (1-3 &#215; 109 dm3 mol-1 s-1 were lower compared to the rate observed with the &#8226;OH radical. The transient absorption spectra obtained in the reaction of e-aq with three isomers exhibited a weak broad band around 340-410 nm. The absorption maxima of the intermediates formed in the &#8226;OH and SO&#8226;-4 reactions were centred around 320-330 nm (&#949;= 2450- 3500 dm3 mol-1 cm-1/ with an additional broad peak in the range 460-520 nm which are attributed to the corresponding &#8226;OH adducts. The spectra in the O&#8226;- reaction have absorption maxima between 300 and 320 nm and it reacts both by addition and H-abstraction from the CH3 group. A reaction mechanism consistent with the observed results is proposed

    Introduction and methodology – Guidelines on Parenteral Nutrition, Chapter 1

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    Guidelines for Parenteral Nutrition were prepared by the German Society for Nutritional Medicine (http://www.dgem.de/), in collaboration with other medical associations to provide guidance for quality assurance for parenteral nutrition (PN) practice, and to promoting health and quality of life of patients concerned. A coordination team proposed topics, working group leaders who along with working group members performed systematic literatur searches and drafted recommendations in a nominal group process. Recommendations were discussed and agreed upon in a structured consensus conference process, followed by a Delphi consensus. The current English version of the guidelines was written and updated during the period between the last quarter of 2007 and the first quarter of 2009. The recommendations of the guidelines should be reviewed, and if necessary updated five years after publication
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