979 research outputs found

    Mast cell activation symptoms are prevalent in Long-COVID

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    OBJECTIVES: Hyper-inflammation caused by COVID-19 may be mediated by mast cell activation (MCA) which has also been hypothesized to cause Long-COVID (LC) symptoms. We determined prevalence/severity of MCA symptoms in LC. METHODS: Adults in LC-focused Facebook support groups were recruited for online assessment of symptoms before and after COVID-19. Questions included presence and severity of known MCA and LC symptoms and validated assessments of fatigue and quality of life. General population controls and mast cell activation syndrome (MCAS) patients were recruited for comparison if they were ≥18 years of age and never had overt COVID-19 symptoms. RESULTS: There were 136 LC subjects (89.7% females, age 46.9 ±12.9 years), 136 controls (65.4% females, age 49.2 ±15.5), and 80 MCAS patients (85.0% females, age 47.7 ±16.4). Pre-COVID-19 LC subjects and controls had virtually identical MCA symptom and severity analysis. Post-COVID-19 LC subjects and MCAS patients prior to treatment had virtually identical MCA symptom and severity analysis. CONCLUSIONS: MCA symptoms were increased in LC and mimicked the symptoms and severity reported by patients who have MCAS. Increased activation of aberrant mast cells induced by SARS-CoV-2 infection by various mechanisms may underlie part of the pathophysiology of LC, possibly suggesting routes to effective therapy

    Three dimensional mapping of Fe dopants in ceria nanocrystals using direct spectroscopic electron tomography

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    Electron tomography is a powerful technique for the 3D characterization of the morphology of nanostructures. Nevertheless, resolving the chemical composition of complex nanostructures in 3D remains challenging and the number of studies in which electron energy loss spectroscopy (EELS) is combined with tomography is limited. During the last decade, dedicated reconstruction algorithms have been developed for HAADF-STEM tomography using prior knowledge about the investigated sample. Here, we will use the prior knowledge that the experimental spectrum of each reconstructed voxel is a linear combination of a well-known set of references spectra in a so-called direct spectroscopic tomography technique. Based on a simulation experiment, it is shown that this technique provides superior results in comparison to conventional reconstruction methods for spectroscopic data, especially for spectrum images containing a relatively low signal to noise ratio. Next, this technique is used to investigate the spatial distribution of Fe dopants in Fe:Ceria nanoparticles in 3D. It is shown that the presence of the Fe2+ dopants is correlated with a reduction of the Ce atoms from Ce4+ towards Ce3+. In addition, it is demonstrated that most of the Fe dopants are located near the voids inside the nanoparticle

    Training basic laparoscopic skills using a custom-made video game

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    Video games are accepted and used for a wide variety of applications. In the medical world, research on the positive effects of playing games on basic laparoscopic skills is rapidly increasing. Although these benefits have been proven several times, no institution actually uses video games for surgical training. This Short Communication describes some of the theoretical backgrounds, development and underlying educational foundations of a specifically designed video game and custom-made hardware that takes advantage of the positive effects of games on basic laparoscopic skills

    Seroprevalence of hantaviruses and Leptospira in muskrat and coypu trappers in the Netherlands, 2016.

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    Aims: Seoul orthohantavirus (SEOV) and Leptospira spp. are zoonotic pathogens with rats as main reservoir. Recently, the presence of SEOV in brown rats was reported in one region in the Netherlands. Brown rats are a frequent bycatch in traps placed to catch muskrats (Ondatra zibethicus) and coypus (Myocastor coypus), and thus are a potential health risk for trappers. It was our aim to determine the seroprevalence of orthohantavirus, specifically SEOV, and Leptospira spp in Dutch trappers. Methods and results: Participating trappers provided serum samples and completed an online questionnaire. The serum was tested for the presence of antibodies against six orthohantaviruses and eight Leptospira serovars. Two hundred-sixty trappers completed the online questionnaire (65%), and 246 (61%) and 162 (40%) serum samples were tested for relevant orthohantaviruses and Leptospira spp., respectively. The seroprevalence of Puumala orthohantavirus in Dutch trappers was 0.4% (95% CI: 0.1-2.3%). None of the participants tested positive for SEOV. The seroprevalence of leptospirosis was 1.2% (95% CI: 0.3-4.4%), although Leptospira spp. are present in brown rats in the Netherlands.Significance of study: The results indicate that the infections with orthohantaviruses and leptospires is low for muskrat and coypu trappers

    Best Practices for Building Interprofessional Telehealth: Report of a Conference

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    The Arizona Biomedical Research Centre (ABRC) has funded a series of workshops and conferences since 2016 to build the capacity of local, tribal, and state agencies, healthcare delivery organizations, and non-governmental organizations to engage in meaningful research related to health disparities. With the COVID-19 pandemic, the use of telehealth has dramatically increased, particularly in nursing, occupational therapy (OT), physical therapy (PT), and speech-language pathology (SLP). The purpose of this paper is to summarize the presentations and discussion from the conference titled “Telerehabilitation and Telepractice: An Interprofessional Conference to Build Connections and Best Practices,” held remotely on March 4-5, 2021. Terminology and concepts from the conference were debated, modified, and refined, based on an interprofessional audience. Presenters at the conference, all leaders in their field, discussed the current status of telehealth in their professions, including best practices, challenges, future trends, and research needs

    Structure and vacancy distribution in copper telluride nanoparticles influence plasmonic activity in the near-infrared

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    Copper chalcogenides find applications in different domains including photonics, photothermal therapy and photovoltaics. CuTe nanocrystals have been proposed as an alternative to noble metal particles for plasmonics. Although it is known that deviations from stoichiometry are a prerequisite for plasmonic activity in the near-infrared, an accurate description of the material and its (optical) properties is hindered by an insufficient understanding of the atomic structure and the influence of defects, especially for materials in their nanocrystalline form. We demonstrate that the structure of Cu1.5±xTe nanocrystals can be determined using electron diffraction tomography. Real-space high-resolution electron tomography directly reveals the three-dimensional distribution of vacancies in the structure. Through first-principles density functional theory, we furthermore demonstrate that the influence of these vacancies on the optical properties of the nanocrystals is determined. Since our methodology is applicable to a variety of crystalline nanostructured materials, it is expected to provide unique insights concerning structure–property correlations

    Geometric reconstruction methods for electron tomography

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    Electron tomography is becoming an increasingly important tool in materials science for studying the three-dimensional morphologies and chemical compositions of nanostructures. The image quality obtained by many current algorithms is seriously affected by the problems of missing wedge artefacts and nonlinear projection intensities due to diffraction effects. The former refers to the fact that data cannot be acquired over the full 180180^\circ tilt range; the latter implies that for some orientations, crystalline structures can show strong contrast changes. To overcome these problems we introduce and discuss several algorithms from the mathematical fields of geometric and discrete tomography. The algorithms incorporate geometric prior knowledge (mainly convexity and homogeneity), which also in principle considerably reduces the number of tilt angles required. Results are discussed for the reconstruction of an InAs nanowire

    Police legitimacy among immigrants in Europe: institutional frames and group position

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    Research on the antecedents of police legitimacy has begun to stress the relevance of a wide range of factors – beyond performance – in shaping public judgements of police (e.g. Jackson et al 2012; Antrobus et al 2015; Mehozay and Factor 2016; Weitzer and Tuch 2006). The ways in which people experience not just policing and but also their wider social, cultural and economic environment – and the location of both police and policed within structures of power, authority and affect – have important effects on lay judgements of police which, in turn, constitute the empirical legitimacy of this foundational state institution

    Measuring Lattice Strain in Three Dimensions through Electron Microscopy

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    The three-dimensional (3D) atomic structure of nanomaterials, including strain, is crucial to understand their properties. Here, we investigate lattice strain in Au nanodecahedra using electron tomography. Although different electron tomography techniques enabled 3D characterizations of nanostructures at the atomic level, a reliable determination of lattice strain is not straightforward. We therefore propose a novel model-based approach from which atomic coordinates are
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