Among the different graphene derivatives, graphene oxide is the most intensively studied material as it exhibits reliable and repeatable resistive switching. The operative mechanisms that are responsible for resistive switching are being intensively investigated, and three models explaining the change in the resistive states have been developed. These models are grounded in the metallic-like filamentary conduction, contact resistance modification and the oxidation of/reduction in the graphene oxide bulk.
View Article and Find Full Text PDFThe paper presents a program for simulating electron scattering in layered materials . Calculations show that the absorbed energy density is three-dimensional, while the contribution of the forward-scattered electrons is better described by a power function rather than the commonly used Gaussian. It is shown that for the practical correction of the proximity effect, it is possible, nevertheless, to use the classical two-dimensional proximity function containing three parameters: α, β, η.
View Article and Find Full Text PDFBackground: Data on the species diversity and distribution of pteridophytes (lycophytes and ferns) in the Urals and adjacent areas are presented. The dataset includes 13,742 observations of two classes Lycopodiopsida and Polypodiopsida. In total, the dataset contains information on 16 families, 28 generas, 65 species, four subspecies and nine interspecies hybrids.
View Article and Find Full Text PDFBackground: The "Flora of Russia" project on iNaturalist brought together professional scientists and amateur naturalists from all over the country. Over 10,000 people were involved in the data collection.
New Information: Within 20 months, the participants accumulated 750,143 photo observations of 6,857 species of the Russian flora.
United European Gastroenterol J
March 2017
Background: The quality of colonoscopy has been related to a higher risk of interval cancer, and this issue has been addressed extensively in developed countries. The aim of our study was to explore the main quality indicators of colonoscopy in a large emerging country.
Methods: Consecutive patients referred for colonoscopy in 14 centres were prospectively included between July and October 2014.