1,740 research outputs found

    The effect of ultraviolet C radiation against different N95 respirators inoculated with SARS-CoV-2

    Get PDF
    OBJECTIVES: There are currently no studies that have examined whether one dosage can be uniformly applied to different respirator types to effectively decontaminate SARS-CoV-2 on N95 filtering facepiece respirators (FFRs). Health care workers have been using this disinfection method during the pandemic. Our objective was to determine the effect of UVC on SARS-CoV-2 inoculated N95 respirators and whether this was respirator material/model type dependent. METHODS: Four different locations (facepiece and strap) on five different N95 FFR models (3M 1860, 8210, 8511, 9211; Moldex 1511) were inoculated with a 10 μL drop of SARS-CoV-2 viral stock (8 × 10 RESULTS: UVC delivered using a dose of 1.5 J/cm(2), to each side, was an effective method of decontamination for the facepieces of 3 M 1860 and Moldex 1511, and for the straps of 3 M 8210 and the Moldex 1511. CONCLUSION: This dose is an appropriate decontamination method to facilitate the reuse of respirators for healthcare personnel when applied to specific models/materials. Also, some straps may require additional disinfection to maximize the safety of frontline workers. Implementation of widespread UVC decontamination methods requires careful consideration of model, material type, design, and fit-testing following irradiation

    Nanoparticle shapes of LiMnPO4, Li+ diffusion orientation and diffusion coefficients for high volumetric energy Li+ ion cathodes

    Get PDF
    Nanoparticles of LiMnPO₄ were fabricated in rod, elongated as well as cubic shapes. The 1D Li⁺ preferred diffusion direction for each shape was determined via electron diffraction spot patterns. The shape of nano-LiMnPO₄ varied the diffusion coefficient of Li⁺ because the Li⁺ diffusion direction and the path length were different. The particles with the shortest dimension along the b-axis provided the highest diffusion coefficient, resulting in the highest gravimetric capacity of 135, 100 and 60 mAh g⁻¹ at 0.05C, 1C and 10C, respectively. Using ball-milling, a higher loading of nano-LiMnPO₄ in the electrode was achieved, increasing the volumetric capacity to 263 mAh cm⁻³, which is ca. 3.5 times higher than the one obtained by hand-mixing of electrode materials. Thus, the electrochemical performance is governed by both the diffusion coefficient of Li⁺, which is dependent on the shape of LiMnPO₄ nanoparticles and the secondary composite structure

    Entropic effects on the Size Evolution of Cluster Structure

    Full text link
    We show that the vibrational entropy can play a crucial role in determining the equilibrium structure of clusters by constructing structural phase diagrams showing how the structure depends upon both size and temperature. These phase diagrams are obtained for example rare gas and metal clusters.Comment: 5 pages, 3 figure

    Vesicle-Like Biomechanics Governs Important Aspects of Nuclear Geometry in Fission Yeast

    Get PDF
    It has long been known that during the closed mitosis of many unicellular eukaryotes, including the fission yeast (Schizosaccharomyces pombe), the nuclear envelope remains intact while the nucleus undergoes a remarkable sequence of shape transformations driven by elongation of an intranuclear mitotic spindle whose ends are capped by spindle pole bodies embedded in the nuclear envelope. However, the mechanical basis of these normal cell cycle transformations, and abnormal nuclear shapes caused by intranuclear elongation of microtubules lacking spindle pole bodies, remain unknown. Although there are models describing the shapes of lipid vesicles deformed by elongation of microtubule bundles, there are no models describing normal or abnormal shape changes in the nucleus. We describe here a novel biophysical model of interphase nuclear geometry in fission yeast that accounts for critical aspects of the mechanics of the fission yeast nucleus, including the biophysical properties of lipid bilayers, forces exerted on the nuclear envelope by elongating microtubules, and access to a lipid reservoir, essential for the large increase in nuclear surface area during the cell cycle. We present experimental confirmation of the novel and non-trivial geometries predicted by our model, which has no free parameters. We also use the model to provide insight into the mechanical basis of previously described defects in nuclear division, including abnormal nuclear shapes and loss of nuclear envelope integrity. The model predicts that (i) despite differences in structure and composition, fission yeast nuclei and vesicles with fluid lipid bilayers have common mechanical properties; (ii) the S. pombe nucleus is not lined with any structure with shear resistance, comparable to the nuclear lamina of higher eukaryotes. We validate the model and its predictions by analyzing wild type cells in which ned1 gene overexpression causes elongation of an intranuclear microtubule bundle that deforms the nucleus of interphase cells

    Effectiveness of integrating a pragmatic pathway for prescribing liraglutide 3.0mg in weight management services (STRIVE study): a multicentre, open-label, parallel-group, randomized controlled trial

    Get PDF
    Summary. Background: An effective prescribing pathway for liraglutide 3 mg, an approved obesity pharmacotherapy, may improve treatment access. This trial compared a targeted prescribing pathway for liraglutide 3 mg with multiple stopping rules in specialist weight management services (SWMS) to standard SWMS care. Methods: This phase four, two-year, multicentre, open-label, parallel-group, real-world randomized clinical trial (ClinicalTrials.gov: NCT03036800) enrolled adults with BMI ≥35 kg/m2 plus prediabetes, type 2 diabetes, hypertension or sleep apnoea from five SWMS in Ireland and UK. Participants were randomly allocated (2:1, stratified by centre and BMI) to SWMS care plus a targeted prescribing pathway for once daily subcutaneous liraglutide 3 mg (intervention) with stopping rules at 16 (≥5% weight loss, WL), 32 (≥10% WL) and 52 weeks (≥15% WL) or to SWMS care alone (control) through an online randomization service. The primary outcome was WL ≥15% at 52 weeks, assessed by complete cases analysis. All randomized participants were included in safety analysis. Findings From November 28, 2017 to February 28, 2020, 434 participants were screened, and 392 randomized (260 intervention; 132 control), while 294 (201 intervention; 93 control) included in the 52 weeks complete case analysis. More intervention than control participants achieved WL ≥15% at 52 weeks [51/201 (25.4%) vs 6/93 (6.5%); odds ratio 5.18; 95% CI 2.09, 12.88; p < 0.0001]. More adverse events occurred in the intervention (238/260, 91.5%; two deaths) than control (89/132, 67.4%; no deaths) group. Interpretation: A targeted prescribing pathway for liraglutide 3 mg helps more people achieve ≥15% WL at 52 weeks than standard care alone

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

    Get PDF
    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be 24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with δ<+34.5\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie
    corecore