1,083 research outputs found

    Three-dimensional Quantum-size Effect In Chemically Deposited Cadmium Selenide Films

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    Optical band gaps, Eg, up to 0.5 eV higher than in single-crystal samples, are observed for chemically deposited films of CdSe and explained in terms of a quantum-size effect, whereby the electrons are localized in individual crystallites. The increase in Eg depends strongly on deposition temperature, with the greatest increase obtained at the lowest temperature. Annealing at temperatures above the deposition temperature causes a decrease in Eg; this decrease is stronger at higher annealing temperature. Structural studies of the as-deposited layers showed them to be composed of microcrystalline, cubic CdSe, and electron microscopy resolved them into individual crystallites of typically 4080-A diameter, depending on deposition temperature. This is the first example reported of a three-dimensional quantum-size effect in a film. © 1987 The American Physical Society.3684215422

    Mobile information access in the real world: A story of three wireless devices

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    This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2008 ElsevierThe importance of the user perspective to the wireless information access experience cannot be understated: simply put, users will not indulge in devices that are perceived to be difficult to use and in technologies that do not offer quality infotainment – combined information and entertainment – content. In this paper, we investigate the impact that mobile devices have on the user wireless infotainment access experience in practice. To this end, we have undertaken an empirical study placed in a ‘real-world’ setting, in which participants undertook typical infotainment access tasks on three different wireless-enabled mobile devices: a laptop, a personal digital assistant and a head mounted display device. Results show that, with the exception of participants’ level of self-consciousness when using such devices in public environments, the user wireless information access experience is generally unaffected by device type. Location was shown, though, to be a significant factor when users engage in tasks such as listening to online music or navigation. Whilst the interaction between device and environment was found to influence entertainment-related tasks in our experiments, the informational ones were not affected. However, the interaction effects between device and user type was found to affect both types of tasks. Lastly, a user’s particular computing experience was shown to influence the perceived ease of wireless information access only in the case of online searching, irrespective of whether this is done for primarily informational purposes or entertainment ones

    A Child With Radius Aplasia, Cleft of Lip and Palate, Microcephaly, and Unusual Chromosome Findings

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    We report a child with malformation syndrome of microcephaly, asymmetrical radius aplasia, and cleft of lip and palate, who was mosaic for a chromosome marker and/or ring of unknown origin. In view of the reported cases of limb deficiency with chromosome abnormalities and the unlikelihood that the patient has a recognized genetic syndrome, the cause of the patient’s syndrome may well be the extra chromosomal material

    Linkage analysis in a large kindred with autosomal dominant transmission of polyglandular autoimmune disease type II (Schmidt syndrome)

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    Schmidt syndrome (PGA syndrome type II) is a rare condition characterized by polyglandular failure. It is an autosomal dominant trait with variable expressivity that was inherited over four generations in an Indiana kindred. Association of HLA-B8 has been reported with Schmidt syndrome. Our proband is a 12-year-old boy with Addison disease, insulin dependent diabetes mellitus (IDDM), and vitiligo. Two of his eight sibs had either IDDM (sister) or vitiligo and hyperthyroidism (brother). His mother had hypothyroidism. Seven members of earlier generations apparently were also affected. We obtained peripheral blood for HLA and genetic analysis from 21 relatives in a family with 8 Schmidt syndrome individuals in three generations. HLA studies on 15 affected and unaffected relatives showed only 2 of 7 persons with B8-containing haplotypes. Therefore, no association exists between the B8-containing haplotype and the syndrome. We identified informative marker loci. No evidence for linkage of the Schmidt locus to any of the 14 markers was found and close linkage to esterase D and adenylate kinase and possibly properdin factor B was excluded

    Brief clinical report: prune belly syndrome in an anencephalic male

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    We describe a postmature anencephalic infant with atrophy of the abdominal musculature (prune belly syndrome). Other associations of these conditions are noted

    Light Induced Increase of Electron Diffusion Length in a p n Junction Type CH3NH3PbBr3 Perovskite Solar Cell

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    High band gap, high open circuit voltage solar cells with methylammonium lead tribromide MAPbBr3 perovskite absorbers are of interest for spectral splitting and photoelectrochemical applications, because of their good performance and ease of processing. The physical origin of high performance in these and similar perovskite based devices remains only partially understood. Using cross sectional electron beaminduced current EBIC measurements, we find an increase in carrier diffusion length in MAPbBr3 Cl based solar cells upon low intensity a few percent of 1 sun intensity blue laser illumination. Comparing dark and illuminated conditions, the minority carrier electron diffusion length increases about 3.5 times from Ln 100 50 nm to 360 22 nm. The EBIC cross section profile indicates a p amp; 8722;n structure between the n FTO TiO2 and p perovskite, rather than the p amp; 8722;i amp; 8722;n structure, reported for the iodide derivative. On the basis of the variation in space charge region width with varying bias, measured by EBIC and capacitance amp; 8722;voltage measurements, we estimate the net doping concentration in MAPbBr3 Cl to be 3 amp; 8722;6 1017 cm amp; 8722;

    Epidemiological surveillance study of female genital mutilation in the UK

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    OBJECTIVES: Describe cases of female genital mutilation (FGM) presenting to consultant paediatricians and sexual assault referral centres (SARCs), including demographics, medical symptoms, examination findings and outcome. DESIGN: The well-established epidemiological surveillance study performed through the British Paediatric Surveillance Unit included FGM on the monthly returns. SETTING: All consultant paediatricians and relevant SARC leads across the UK and Ireland. PATIENTS: Under 16 years old with FGM. INTERVENTIONS: Data on cases from November 2015 to November 2017 and 12 months later meeting the case definition of FGM. MAIN OUTCOMES MEASURES: Returns included 146 cases, 103 (71%) had confirmed FGM and 43 (29%) did not meet the case definition. There were none from Northern Ireland. RESULTS: The mean reported age was 3 years. Using the WHO classification of FGM, 58% (n=60) had either type 1 or type 2, 8% (n=8) had type 3 and 21% (n=22) had type 4. 13% (n=13) of the cases were not classified and none had piercings or labiaplasty. The majority, 70% had FGM performed in Africa with others from Europe, Middle East and South-East Asia. There were few physical and mental health symptoms. Only one case resulted in a successful prosecution. CONCLUSIONS: There were low numbers of children presenting with FGM and in the 2 years there was only one prosecution. The findings may be consistent with attitude changes in FGM practising communities and those at risk should be protected and supported by culturally competent national policie

    Evaluation of machine-learning methods for ligand-based virtual screening

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    Machine-learning methods can be used for virtual screening by analysing the structural characteristics of molecules of known (in)activity, and we here discuss the use of kernel discrimination and naive Bayesian classifier (NBC) methods for this purpose. We report a kernel method that allows the processing of molecules represented by binary, integer and real-valued descriptors, and show that it is little different in screening performance from a previously described kernel that had been developed specifically for the analysis of binary fingerprint representations of molecular structure. We then evaluate the performance of an NBC when the training-set contains only a very few active molecules. In such cases, a simpler approach based on group fusion would appear to provide superior screening performance, especially when structurally heterogeneous datasets are to be processed

    Quantum line bundles on noncommutative sphere

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    Noncommutative (NC) sphere is introduced as a quotient of the enveloping algebra of the Lie algebra su(2). Using the Cayley-Hamilton identities we introduce projective modules which are analogues of line bundles on the usual sphere (we call them quantum line bundles) and define a multiplicative structure in their family. Also, we compute a pairing between certain quantum line bundles and finite dimensional representations of the NC sphere in the spirit of the NC index theorem. A new approach to constructing the differential calculus on a NC sphere is suggested. The approach makes use of the projective modules in question and gives rise to a NC de Rham complex being a deformation of the classical one.Comment: LaTeX file, 15 pp, no figures. Some clarifying remarks are added at the beginning of section 2 and into section
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