80 research outputs found

    New Experimental limit on Optical Photon Coupling to Neutral, Scalar Bosons

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    We report on the first results of a sensitive search for scalar coupling of photons to a light neutral boson in the mass range of approximately 1.0 milli-electron volts and coupling strength greater than 106^-6 GeV1^-1 using optical photons. This was a photon regeneration experiment using the "light shining through a wall" technique in which laser light was passed through a strong magnetic field upstream of an optical beam dump; regenerated laser light was then searched for downstream of a second magnetic field region optically shielded from the former. Our results show no evidence for scalar coupling in this region of parameter space.Comment: pdf-file, 10 pages, 4 figures, submitted to Physical Review Letter

    New Experimental Limit on Photon Hidden-Sector Paraphoton Mixing

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    We report on the first results of a search for optical-wavelength photons mixing with hypothetical hidden-sector paraphotons in the mass range between 10^-5 and 10^-2 electron volts for a mixing parameter greater than 10^-7. This was a generation-regeneration experiment using the "light shining through a wall" technique in which regenerated photons are searched for downstream of an optical barrier that separates it from an upstream generation region. The new limits presented here are approximately three times more sensitive to this mixing than the best previous measurement. The present results indicate no evidence for photon-paraphoton mixing for the range of parameters investigated.Comment: 9 pages, 3 figure

    Adverse effects of non-steroidal anti-inflammatory drugs in patients with viral respiratory infections: rapid systematic review

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    Objectives: To assess the effects of non-steroidal anti-inflammatory drugs (NSAIDs) in patients with viral respiratory infections on acute severe adverse outcomes, healthcare utilisation, quality of life and long-term survival. Design: Rapid systematic review. Participants: Humans with viral respiratory infections, exposed to systemic NSAIDs. Primary outcomes: Acute severe adverse outcomes, healthcare utilisation, quality of life and long-term survival. Results: We screened 10 999 titles and abstracts and 738 full texts, including 87 studies. No studies addressed COVID-19, Severe Acute Respiratory Syndrome or Middle East Respiratory Syndrome; none examined inpatient healthcare utilisation, quality of life or long-term survival. Effects of NSAIDs on mortality and cardiovascular events in adults with viral respiratory infections are unclear (three observational studies; very low certainty). Children with empyema and gastrointestinal bleeding may be more likely to have taken NSAIDs than children without these conditions (two observational studies; very low certainty). In patients aged 3 years and older with acute respiratory infections, ibuprofen is associated with a higher rate of reconsultations with general practitioners than paracetamol (one randomised controlled trial (RCT); low certainty). The difference in death from all causes and hospitalisation for renal failure and anaphylaxis between children with fever receiving ibuprofen versus paracetamol is likely to be less than 1 per 10 000 (1 RCT; moderate/high certainty). Twenty-eight studies in adults and 42 studies in children report adverse event counts. Most report that no severe adverse events occurred. Due to methodological limitations of adverse event counts, this evidence should be interpreted with caution

    Multimodal recording of brain activity in term newborns during photic stimulation by near-infrared spectroscopy and electroencephalography

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    In this study 14 healthy term newborns (postnatal mean age 2.1 days) underwent photic stimulation during sleep on two different days. Near-infrared spectroscopy (NIRS) and electroencephalography (EEG) was acquired simultaneously. The aims of the study were: to determine (i) the sensitivity and (ii) the repeatability of NIRS to detect the hemodynamic response, (iii) the sensitivity and (iv) the repeatability of EEG to detect a visual evoked potential (VEP), (v) to analyze optical data for the optical neuronal signal, and (vi) to test whether inadequate stimulation could be reason for absent hemodynamic responses. The results of the study were as follows. (i) Sensitivity of NIRS was 61.5% to detect hemodynamic responses; (ii) their reproducibility was 41.7%. A VEP was detected (iii) in 96.3% of all subjects with (iv) a reproducibility of 92.3%. (v) In two measurements data met the criteria for an optical neuronal signal. The noise level was 9.6·10-5% change in optical density. (vi) Insufficient stimulation was excluded as reason for absent hemodynamic responses. We conclude that NIRS is an promising tool to study cognitive activation and development of the brain. For clinical application, however, the sensitivity and reproducibility on an individual level needs to be improved

    Unintended health and societal consequences of international travel measures during the COVID-19 pandemic: A scoping review

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    RATIONALE FOR REVIEW International travel measures to contain the COVID-19 pandemic represent a relatively intrusive form of non-pharmaceutical intervention. To inform decision-making on the (re)implementation, adaptation, relaxation or suspension of such measures, it is essential to not only assess their effectiveness but also their unintended effects. This scoping review maps existing empirical studies on the unintended consequences, both predicted and unforeseen, and beneficial or harmful, of international travel measures. We searched multiple health, non-health and COVID-19-specific databases. The evidence was charted in a map in relation to the study design, intervention and outcome categories identified and discussed narratively. KEY FINDINGS Twenty-three studies met our inclusion criteria-nine quasi-experimental, two observational, two mathematical modelling, six qualitative, and four mixed-methods studies. Studies addressed different population groups across various countries worldwide. Seven studies provided information on unintended consequences of the closure of national borders, six looked at international travel restrictions, and three investigated mandatory quarantine of international travelers. No studies looked at entry and/or exit screening at national borders exclusively, however six studies considered this intervention in combination with other international travel measures. In total, eleven studies assessed various combinations of the aforementioned interventions. The outcomes were mostly referred to by the authors as harmful. Fifteen studies identified a variety of economic consequences, six reported on aspects related to quality of life, well-being, and mental health, and five on social consequences. One study each provided information on equity, equality, and the fair distribution of benefits and burdens, environmental consequences and health system consequences. CONCLUSIONS/RECOMMENDATIONS This scoping review represents the first step towards a systematic assessment of the unintended benefits and harms of international travel measures during COVID-19. The key research gaps identified might be filled with targeted primary research, as well as the additional consideration of gray literature and non-empirical studies

    Travel-related control measures to contain the COVID-19 pandemic: an evidence map

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    OBJECTIVES To comprehensively map the existing evidence assessing the impact of travel-related control measures for containment of the SARS-CoV-2/COVID-19 pandemic. DESIGN Rapid evidence map. DATA SOURCES MEDLINE, Embase and Web of Science, and COVID-19 specific databases offered by the US Centers for Disease Control and Prevention and the WHO. ELIGIBILITY CRITERIA We included studies in human populations susceptible to SARS-CoV-2/COVID-19, SARS-CoV-1/severe acute respiratory syndrome, Middle East respiratory syndrome coronavirus/Middle East respiratory syndrome or influenza. Interventions of interest were travel-related control measures affecting travel across national or subnational borders. Outcomes of interest included infectious disease, screening, other health, economic and social outcomes. We considered all empirical studies that quantitatively evaluate impact available in Armenian, English, French, German, Italian and Russian based on the team's language capacities. DATA EXTRACTION AND SYNTHESIS We extracted data from included studies in a standardised manner and mapped them to a priori and (one) post hoc defined categories. RESULTS We included 122 studies assessing travel-related control measures. These studies were undertaken across the globe, most in the Western Pacific region (n=71). A large proportion of studies focused on COVID-19 (n=59), but a number of studies also examined SARS, MERS and influenza. We identified studies on border closures (n=3), entry/exit screening (n=31), travel-related quarantine (n=6), travel bans (n=8) and travel restrictions (n=25). Many addressed a bundle of travel-related control measures (n=49). Most studies assessed infectious disease (n=98) and/or screening-related (n=25) outcomes; we found only limited evidence on economic and social outcomes. Studies applied numerous methods, both inferential and descriptive in nature, ranging from simple observational methods to complex modelling techniques. CONCLUSIONS We identified a heterogeneous and complex evidence base on travel-related control measures. While this map is not sufficient to assess the effectiveness of different measures, it outlines aspects regarding interventions and outcomes, as well as study methodology and reporting that could inform future research and evidence synthesis

    Исследование закономерностей модификации стали 12Х18Н10Т высокоинтенсивной имплантацией ионов азота

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    В данной работе представлены результаты по изучению формирования пучков ионов азота и их воздействие на поверхность стали 12Х18Н10Т в условиях компенсации распыления. Также было изучено формирование высокоинтенсивных пучков ионов титана. Впервые описан метод измерения глубины легированной примеси при помощи прибора CALOTEST.This paper presents the results of studying the formation of nitrogen ion beams and their effect on the surface of 12X18H10T steel under conditions of sputtering compensation. The formation of high-intensity beams of titanium ions was also studied. For the first time, a method for measuring the depth of an alloyed impurity using the CALOTEST device is described

    Speech-evoked activation in adult temporal cortex measured using functional near-infrared spectroscopy (fNIRS): Are the measurements reliable?

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    Functional near-infrared spectroscopy (fNIRS) is a silent, non-invasive neuroimaging technique that is potentially well suited to auditory research. However, the reliability of auditory-evoked activation measured using fNIRS is largely unknown. The present study investigated the test-retest reliability of speech-evoked fNIRS responses in normally-hearing adults. Seventeen participants underwent fNIRS imaging in two sessions separated by three months. In a block design, participants were presented with auditory speech, visual speech (silent speechreading), and audiovisual speech conditions. Optode arrays were placed bilaterally over the temporal lobes, targeting auditory brain regions. A range of established metrics was used to quantify the reproducibility of cortical activation patterns, as well as the amplitude and time course of the haemodynamic response within predefined regions of interest. The use of a signal processing algorithm designed to reduce the influence of systemic physiological signals was found to be crucial to achieving reliable detection of significant activation at the group level. For auditory speech (with or without visual cues), reliability was good to excellent at the group level, but highly variable among individuals. Temporal-lobe activation in response to visual speech was less reliable, especially in the right hemisphere. Consistent with previous reports, fNIRS reliability was improved by averaging across a small number of channels overlying a cortical region of interest. Overall, the present results confirm that fNIRS can measure speech-evoked auditory responses in adults that are highly reliable at the group level, and indicate that signal processing to reduce physiological noise may substantially improve the reliability of fNIRS measurements
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