8,088 research outputs found

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    Random control study looking at the use of 1320 nm Nd:YAG laser and intense pulsed light source for non-ablative skin rejuvenation in Chinese

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    Measurement of overall insecticidal effects in experimental hut trials

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    BACKGROUND: The 'overall insecticidal effect' is a key measure used to evaluate public health pesticides for indoor use in experimental hut trials. It depends on the proportion of mosquitoes that are killed out of those that enter the treated hut, intrinsic mortality in the control hut, and the ratio of mosquitoes entering the treatment hut to those entering the control hut. This paper critically examines the way the effect is defined, and discusses how it can be used to infer effectiveness of intervention programmes. FINDINGS: The overall insecticidal effect, as defined by the World Health Organization in 2006, can be negative when deterrence from entering the treated hut is high, even if all mosquitoes that enter are killed, wrongly suggesting that the insecticide enhances mosquito survival. Also in the absence of deterrence, even if the insecticide kills all mosquitoes in the treatment hut, the insecticidal effect is less than 100%, unless intrinsic mortality is nil. A proposed alternative definition for the measurement of the overall insecticidal effect has the desirable range of 0 to 1 (100%), provided mortality among non-repelled mosquitoes in the treated hut is less than the corresponding mortality in the control hut. This definition can be built upon to formulate the coverage-dependent insecticidal effectiveness of an intervention programme. Coverage-dependent population protection against feeding can be formulated similarly. CONCLUSIONS: This paper shows that the 2006 recommended quantity for measuring the overall insecticidal effect is problematic, and proposes an alternative quantity with more desirable propertie

    askMEDLINE: a free-text, natural language query tool for MEDLINE/PubMed

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    BACKGROUND: Plain language search tools for MEDLINE/PubMed are few. We wanted to develop a search tool that would allow anyone using a free-text, natural language query and without knowing specialized vocabularies that an expert searcher might use, to find relevant citations in MEDLINE/PubMed. This tool would translate a question into an efficient search. RESULTS: The accuracy and relevance of retrieved citations were compared to references cited in BMJ POEMs and CATs (critically appraised topics) questions from the University of Michigan Department of Pediatrics. askMEDLINE correctly matched the cited references 75.8% in POEMs and 89.2 % in CATs questions on first pass. When articles that were deemed to be relevant to the clinical questions were included, the overall efficiency in retrieving journal articles was 96.8% (POEMs) and 96.3% (CATs.) CONCLUSION: askMEDLINE might be a useful search tool for clinicians, researchers, and other information seekers interested in finding current evidence in MEDLINE/PubMed. The text-only format could be convenient for users with wireless handheld devices and those with low-bandwidth connections in remote locations

    Diffuse large B-cell lymphoma of the central nervous system in mycophenolate mofetil-treated patients with systemic lupus erythematosus

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    We report the third case of primary lymphoma of the central nervous system (PCNSL) in a patient with systemic lupus erythematosus (SLE) given long-term mycophenolate mofetil (MMF). Our 43-year-old patient has a history of lupus nephritis and has been treated with MMF 500 mg/day in addition to azathioprine (AZA) for 8 years. She presented with subacute left-sided weakness. Magnetic resonance imaging revealed a gadoliniumenhancing mass in the right parietal region which was isointense on T2-weighted imaging. Brain biopsy revealed diffuse sheets of large lymphoid cells which demonstrated strong membranous expression of CD20 by immunohistochemistry and positive signal for Epstein Bar virus (EBV)–encoded RNA by in-situ hybridization study. Complete remission of PCNSL was achieved after discontinuation of MMF and administration of rituximab and whole brain radiotherapy. Patients with SLE are predisposed to development of lymphoma regardless of immunosuppressive use. One meta-analysis found that non-Hodgkin’s lymphoma was more common in SLE patients with a standardized incidence rate ranging from 5.2 to 44.4. However, the development of PCNSL secondary to immunosuppressive use is being increasingly recognised especially in MMF-treated renal transplant recipients with onset of PCNSL after a median of 14 months. It has also been described in some MMF-treated autoimmune conditions such as myasthenia gravis, dermatomyositis and relapsing polychondritis. Although AZA in combination with corticosteroids has been shown to predispose post-renal transplant patients to lymphoproliferative disease with a relative risk of 12.7, the association of AZA and EBV-related lymphoma is rare. The approach to management of this condition includes withdrawal of MMF and judicious use of future immunosuppressive agents.published_or_final_versionThe 15th Medical Research Conference (15th MRC), Department of Medicine, University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16 n. 1, suppl. 1, p. 54, abstract no. 9

    Reducing combinatorial uncertainties: A new technique based on MT2 variables

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    We propose a new method to resolve combinatorial ambiguities in hadron collider events involving two invisible particles in the final state. This method is based on the kinematic variable MT2 and on the MT2-assisted-on-shell reconstruction of invisible momenta, that are reformulated as `test' variables Ti of the correct combination against the incorrect ones. We show how the efficiency of the single Ti in providing the correct answer can be systematically improved by combining the different Ti and/or by introducing cuts on suitable, combination-insensitive kinematic variables. We illustrate our whole approach in the specific example of top anti-top production, followed by a leptonic decay of the W on both sides. However, by construction, our method is also directly applicable to many topologies of interest for new physics, in particular events producing a pair of undetected particles, that are potential dark-matter candidates. We finally emphasize that our method is apt to several generalizations, that we outline in the last sections of the paper.Comment: 1+23 pages, 8 figures. Main changes in v3: (1) discussion at the end of sec. 2 improved; (2) added sec. 4.2 about the method's dependence on mass information. Matches journal versio

    Using an imperfect photonic network to implement random unitaries

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    We numerically investigate the implementation of Haar-random unitarity transformations and Fourier transformations in photonic devices consisting of beam splitters and phase shifters, which are used for integrated photonics implementations of boson sampling. The distribution of reflectivities required to implement an arbitrary unitary transformation is skewed towards low values, and this skew becomes stronger the larger the number of modes. A realistic implementation using Mach-Zehnder interferometers is incapable of achieving the low values required and thus has limited fidelity. We show that numerical optimisation and adding extra beam splitters to the network can help to restore fidelity

    Chronology of martian breccia NWA 7034 and the formation of the martian crustal dichotomy

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    This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). The attached file is the published version of the article

    Chip-based array of near-identical, pure, heralded single-photon sources

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    Interference between independent single photons is perhaps the most fundamental interaction in quantum optics. It has become increasingly important as a tool for optical quantum information science, as one of the rudimentary quantum operations, together with photon detection, for generating entanglement between non-interacting particles. Despite this, demonstrations of large-scale photonic networks involving more than two independent sources of quan- tum light have been limited due to the difficulty in constructing large arrays of high-quality, single-photon sources. Here, we solve the key challenge, reporting on a novel array of five near-identical, low-loss, high-purity, heralded single-photon sources using spontaneous four-wave mixing on a silica chip. We verify source quality through a series of heralded Hong – Ou – Mandel (HOM) experiments, and further report the experimental three-photon extension of the HOM interference effect, which maps out for the first time, to our knowledge, the interference landscape between three independent single-photon sources
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