689 research outputs found

    Decyl­ammonium octa­noate

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    The title compound, C10H24N+·C8H15O2 −, forms a layered structure in which inter­molecular N+—H⋯O hydrogen bonds connect anions and cations, forming a two-dimensional network parallel to (010). The n-alkyl chains of the decyl­ammonium cations pack according to an ortho­rhom­bic ‘subcell’ with approximate dimensions 5.1 × 7.3 Å, and they are significantly distorted from planarity

    GPs' decisions on drug treatment for patients with high cholesterol values: A think-aloud study

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    BACKGROUND: The purpose was to examine how General Practitioners (GPs) use clinical information and rules from guidelines in their decisions on drug treatment for high cholesterol values. METHODS: Twenty GPs were presented with six case vignettes and were instructed to think aloud while successively more information about a case was presented, and finally to decide if a drug should be prescribed or not. The statements were coded for the clinical information to which they referred and for favouring or not favouring prescription. RESULTS: The evaluation of clinical information was compatible with decision-making as a search for reasons or arguments. Lifestyle-related information like smoking and overweight seemed to be evaluated from different perspectives. A patient's smoking favoured treatment for some GPs and disfavoured treatment for others. CONCLUSIONS: The method promised to be useful for understanding why doctors differ in their decisions on the same patient descriptions and why rules from the guidelines are not followed strictly

    Nickel: A very fast diffuser in silicon

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    Nickel is increasingly used in both IC and photovoltaic device fabrication, yet it has the potential to create highly recombination-active precipitates in silicon. For nearly three decades, the accepted nickel diffusivity in silicon has been DNi(T)=2.3×10exp−3 exp(−0.47 eV/kBT) cm2/s, a surprisingly low value given reports of rapid nickel diffusion in industrial applications. In this paper, we employ modern experimental methods to measure the higher nickel diffusivity DNi(T)=(1.69±0.74)×10exp−4 exp(−0.15±0.04 eV/kBT)  cm2/s. The measured activation energy is close to that predicted by first-principles theory using the nudged-elastic-band method. Our measured diffusivity of nickel is higher than previously published values at temperatures below 1150 °C, and orders of magnitude higher when extrapolated to room temperature.Peer reviewe

    Angle-Resolved Environmental X-Ray Photoelectron Spectroscopy: A New Laboratory Setup for Photoemission Studies at Pressures up to 0.4 Torr

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    The paper presents the development and demonstrates the capabilities of a new laboratory-based environmental X-ray photoelectron spectroscopy system incorporating an electrostatic lens and able to acquire spectra up to 0.4 Torr. The incorporation of a two-dimensional detector provides imaging capabilities and allows the acquisition of angle-resolved data in parallel mode over an angular range of 14° without tilting the sample. The sensitivity and energy resolution of the spectrometer have been investigated by analyzing a standard Ag foil both under high vacuum (10−8 Torr) conditions and at elevated pressures of N2 (0.4 Torr). The possibility of acquiring angle-resolved data at different pressures has been demonstrated by analyzing a silicon/silicon dioxide (Si/SiO2) sample. The collected angle-resolved spectra could be effectively used for the determination of the thickness of the native silicon oxide layer

    A Field Guide to South Dakota Amphibians

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    Amphibians possess a unique combination of physical and biological characteristics which make them sensitive to environmental changes such as pollution and loss of aquatic habitat. Amphibians also play an important role in food chains where they may constitute large portions of other animals\u27 diets. While small fishes or other amphibians prey upon larval amphibians, many mammals and birds rely on a dult amphibians for food. Amphibians also are economically important locally and regionally. For example, local bait dealers sell frogs to anglers and schools buy frogs from biological supply companies for use in classroom dissection exercises. Public interest in, and concern for, the welfare of our natural environment has increased during the past few decades. People are eager to learn and understand more about the plants, animals, and habitats that surround them. Frequently their initial interest is sparked by the ability to identify different species of plants and animals. Although several states have published books , field guides, or technical bulletins regarding amphibians, this is the first comprehensive publication regarding the amphibians of South Dakota. This guide is meant to be useful to anyone wanting to learn more about these often secretive creatures. Included in this guide are tips for identification, brief life histories, and distribution maps of the species that currently or historically have been known to inhabit South Dakota . Distribution maps are based on current (Fischer 1998) and historical (Thompson 1976) distributional records

    Removing orientation-induced localization biases in single-molecule microscopy using a broadband metasurface mask

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    Nanoscale localization of single molecules is a crucial function in several advanced microscopy techniques, including single-molecule tracking and wide-field super-resolution imaging. Until now, a central consideration of such techniques is how to optimize the precision of molecular localization. However, as these methods continue to push towards the nanometre size scale, an increasingly important concern is the localization accuracy. In particular, single fluorescent molecules emit with an anisotropic radiation pattern of an oscillating electric dipole, which can cause significant localization biases using common estimators. Here we present the theory and experimental demonstration of a solution to this problem based on azimuthal filtering in the Fourier plane of the microscope. We do so using a high-efficiency dielectric metasurface polarization/phase device composed of nanoposts with subwavelength spacing. The method is demonstrated both on fluorophores embedded in a polymer matrix and in dL5 protein complexes that bind malachite green

    SimSchool: An Opportunity for Using Serious Gaming for Training Teachers in Rural Areas

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    This article examines the use of simSchool as a training tool for educators working with students with special needs in rural districts. SimSchool is a game which emulates a classroom utilizing a virtual environment. The theory supporting simSchool is explored and current research associated with simSchool is reviewed. The issues surrounding retaining quality special educators in rural districts are discussed. The potential for using simSchool for working with rural special education teachers is explored

    Removing orientation-induced localization biases in single-molecule microscopy using a broadband metasurface mask

    Get PDF
    Nanoscale localization of single molecules is a crucial function in several advanced microscopy techniques, including single-molecule tracking and wide-field super-resolution imaging. Until now, a central consideration of such techniques is how to optimize the precision of molecular localization. However, as these methods continue to push towards the nanometre size scale, an increasingly important concern is the localization accuracy. In particular, single fluorescent molecules emit with an anisotropic radiation pattern of an oscillating electric dipole, which can cause significant localization biases using common estimators. Here we present the theory and experimental demonstration of a solution to this problem based on azimuthal filtering in the Fourier plane of the microscope. We do so using a high-efficiency dielectric metasurface polarization/phase device composed of nanoposts with subwavelength spacing. The method is demonstrated both on fluorophores embedded in a polymer matrix and in dL5 protein complexes that bind malachite green
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