739 research outputs found

    The Yekaterinburg headache initiative: an interventional project, within the Global Campaign against Headache, to reduce the burden of headache in Russia.

    Get PDF
    BACKGROUND: As major causes of global public ill-health and disability, headache disorders are paradoxically ignored in health policy and in planning, resourcing and implementing health services. This is true worldwide. Russia, where the prevalence of headache disorders and levels of attributed disability are well in excess of the global and European averages, is no exception, while arcane diagnoses and treatment preferences are an aggravating factor. Urgent remedial action, with political support, is called for. METHODS: Yekaterinburg, in Sverdlovsk Oblast, is the chosen centre for a demonstrational interventional project in Russia, undertaken within the Global Campaign against Headache. The initiative proposes three actions: 1) raise awareness of need for improvement; 2) design and implement a three-tier model (from primary care to a single highly specialized centre with academic affiliation) for efficient and equitable delivery of headache-related health care; 3) develop a range of educational initiatives aimed at primary-care physicians, non-specialist neurologists, pharmacists and the general public to support the second action. RESULTS AND CONCLUSION: We set these proposals in a context of a health-care needs assessment, and as a model for all Russia. We present and discuss early progress of the initiative, justify the investment of resources required for implementation and call for the political support that full implementation requires. The more that the Yekaterinburg headache initiative can achieve, the more likely it is that this support will be forthcoming

    Basic methodical grounds of teaching international students chinese field-specific terms in technical institutes of higher education (in the context of polymer production)

    Get PDF
    We look at the problem connected with methods of teaching Chinese field-specific terms to international students in technical institutes of higher education. The basis of our research is represented by Chinese scientists’ articles in the sphere of manufacturing polymer. Our research is focused on the solution of problems connected with teaching Chinese field-specific terms to international students in technical institutes of higher education. The task required analysis of teaching and studying issues of field-specific disciplines in Tomsk Polytechnic University, study of terminological processes in Chinese, description of how field-specific terms are adopted from foreign languages into Chinese. Studying the above listed aspects provided a basis for developing a classification of polymer production terms. The way the Chinese language borrows a terminological item is considered when dividing terminological elements into groups for further systematization. We structured our classification of terms and terminological combinations by taking into account the fundamentals of high-molecular composition chemistry for easier understanding of polymer production terminology by teachers and students of technical institutions of higher education

    Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean : evidence for accelerated porosity reduction?

    Get PDF
    Author Posting. © Crown Copyright, 2015. This article is posted here by permission of Oxford University Press for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 204 (2016): 1-20, doi:10.1093/gji/ggv416.The Canada Basin and the southern Alpha-Mendeleev ridge complex underlie a significant proportion of the Arctic Ocean, but the geology of this undrilled and mostly ice-covered frontier is poorly known. New information is encoded in seismic wide-angle reflections and refractions recorded with expendable sonobuoys between 2007 and 2011. Velocity–depth samples within the sedimentary succession are extracted from published analyses for 142 of these records obtained at irregularly spaced stations across an area of 1.9E + 06 km2. The samples are modelled at regional, subregional and station-specific scales using an exponential function of inverse velocity versus depth with regionally representative parameters determined through numerical regression. With this approach, smooth, non-oscillatory velocity–depth profiles can be generated for any desired location in the study area, even where the measurement density is low. Practical application is demonstrated with a map of sedimentary thickness, derived from seismic reflection horizons interpreted in the time domain and depth converted using the velocity–depth profiles for each seismic trace. A thickness of 12–13 km is present beneath both the upper Mackenzie fan and the middle slope off of Alaska, but the sedimentary prism thins more gradually outboard of the latter region. Mapping of the observed-to-predicted velocities reveals coherent geospatial trends associated with five subregions: the Mackenzie fan; the continental slopes beyond the Mackenzie fan; the abyssal plain; the southwestern Canada Basin; and, the Alpha-Mendeleev magnetic domain. Comparison of the subregional velocity–depth models with published borehole data, and interpretation of the station-specific best-fitting model parameters, suggests that sandstone is not a predominant lithology in any of the five subregions. However, the bulk sand-to-shale ratio likely increases towards the Mackenzie fan, and the model for this subregion compares favourably with borehole data for Miocene turbidites in the eastern Gulf of Mexico. The station-specific results also indicate that Quaternary sediments coarsen towards the Beaufort-Mackenzie and Banks Island margins in a manner that is consistent with the variable history of Laurentide Ice Sheet advance documented for these margins. Lithological factors do not fully account for the elevated velocity–depth trends that are associated with the southwestern Canada Basin and the Alpha-Mendeleev magnetic domain. Accelerated porosity reduction due to elevated palaeo-heat flow is inferred for these regions, which may be related to the underlying crustal types or possibly volcanic intrusion of the sedimentary succession. Beyond exploring the variation of an important physical property in the Arctic Ocean basin, this study provides comparative reference for global studies of seismic velocity, burial history, sedimentary compaction, seismic inversion and overpressure prediction, particularly in mudrock-dominated successions

    Molecular Mechanisms Governing IL-24 Gene Expression

    Get PDF
    Interleukin-24 (IL-24) belongs to the IL-10 family of cytokines and is well known for its tumor suppressor activity. This cytokine is released by both immune and nonimmune cells and acts on non-hematopoietic tissues such as skin, lung and reproductive tissues. Apart from its ubiquitous tumor suppressor function, IL-24 is also known to be involved in the immunopathology of autoimmune diseases like psoriasis and rheumatoid arthritis. Although the cellular sources and functions of IL-24 are being increasingly investigated, the molecular mechanisms of IL-24 gene expression at the levels of signal transduction, epigenetics and transcription factor binding are still unclear. Understanding the specific molecular events that regulate the production of IL-24 will help to answer the remaining questions that are important for the design of new strategies of immune intervention involving IL-24. Herein, we briefly review the signaling pathways and transcription factors that facilitate, induce, or repress production of this cytokine along with the cellular sources and functions of IL-24

    Mechanically activated rupture of single covalent bonds: evidence of force induced bond hydrolysis.

    Get PDF
    We have used temperature-dependent single molecule force spectroscopy to stretch covalently anchored carboxymethylated amylose (CMA) polymers attached to an amino-functionalized AFM cantilever. Using an Arrhenius kinetics model based on a Morse potential as a one-dimensional representation of covalent bonds, we have extracted kinetic and structural parameters of the bond rupture process. With 35.5 kJ mol−1, we found a significantly smaller dissociation energy and with 9.0 × 102 s−1 to 3.6 × 103 s−1 also smaller Arrhenius pre-factors than expected for homolytic bond scission. One possible explanation for the severely reduced dissociation energy and Arrhenius pre-factors is the mechanically activated hydrolysis of covalent bonds. Both the carboxylic acid amide and the siloxane bond in the amino-silane surface linker are in principle prone to bond hydrolysis. Scattering, slope and curvature of the scattered data plots indicate that in fact two competing rupture mechanisms are observed

    Chemical reactions at the graphitic step-edge: changes in product distribution of catalytic reactions as a tool to explore the environment within carbon nanoreactors

    Get PDF
    A series of explorative cross-coupling reactions have been developed to investigate the local nanoscale environment around catalytically active Pd(II)complexes encapsulated within hollow graphitised nanofiber (GNF). Two new fullerene-containing and fullerene-free Pd(II)Salen catalysts have been synthesised, and their activity and selectivity towards different substrates has been explored in nanoreactors. The catalysts not only show a significant increase in activity and stability upon heterogenisation at the graphitic step-edges inside the GNF channel, but also exhibit a change in selectivity affected by the confinement which alters the distribution of isomeric products of the reaction. Furthermore, the observed selectivity changes reveal unprecedented details regarding the location and orientation of the catalyst molecules inside the GNF nanoreactor, inaccessible by any spectroscopic or microscopic techniques, thus shedding light on the precise reaction environment inside the molecular catalyst-GNF nanoreactor. Keywords: nanoreactor, catalysis, fullerene, salen, cross-couplin

    Surface activation of Pt nanoparticles synthesised by "hot injection" in the presence of oleylamine.

    Get PDF
    Oleylamine (OA) based "hot injection" colloidal synthesis offers a versatile approach to the synthesis of highly monodisperse metallic and multi-metallic alloyed nanostructures in the absence of potentially toxic and unstable phosphine compounds. For application in heterogeneous catalysis and electrocatalysis, the adsorbed OA species at the metal surfaces should be effectively removed without compromising the structure and composition of the nanostructures. Herein, we investigate the removal of OA from colloidal Pt nanoparticles through 1) "chemical methods" such as washing in acetic acid or ethanol, and ligand exchange with pyridine; and 2) thermal pre-treatment between 185 and 400 °C in air, H2 or Ar atmospheres. The electrochemical reactivity of Pt nanoparticles is acutely affected by the presence of surface organic impurities, making this material ideal for monitoring the effectiveness of OA removal. The results showed that thermal treatment in Ar at temperatures above 400 °C provides highly active particles, with reactivity comparable to the benchmark commercial catalyst, Pt/ETEK. The mechanism involved in thermal desorption of OA was also investigated by thermogravimetric analysis coupled to mass spectrometry (TGA-MS). Oxidation of HCOOH and adsorbed CO in acidic solution were used as test reactions to assess the Pt electrocatalytic activity

    Electrochemical Characterization of Clean Shape-Controlled Pt Nanoparticles Prepared in Presence of Oleylamine/Oleic Acid

    Get PDF
    A collection of shape-controlled Pt nanoparticles has been prepared using two different and previously described methodologies, both using oleylamine/oleic acid as capping material/solvent. A new decontamination protocol is presented to effectively clean the surface of the different nanoparticles thus allowing a full exposure of their surface area and consequently to make the most of their surface structure dependent reactivity. Subsequently, the clean shape-controlled Pt nanoparticles have been electrochemically characterized and their electrocatalytic properties evaluated towards some surface structure reactions of interest. The results indicate that the full characterization of the surface structure cannot be done exclusively by the available microscopy techniques, since it is very difficult to determine the presence of surface defects. Additional surface characterization probes, such as those provided by electrochemical surface sensitive reactions, have been used to assess the surface structure of the samples.This work has been financially supported by the MICINN (Feder) of Spain and Generalitat Valencia through Projects CTQ2013-44083-P and PROMETEOII/2014/013, respectively

    Distribution of crustal types in Canada Basin, Arctic Ocean

    Get PDF
    © The Author(s), 2016. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tectonophysics 691, Part A (2016): 8-30, doi:10.1016/j.tecto.2016.01.038.Seismic velocities determined from 70 sonobuoys widely distributed in Canada Basin were used to discriminate crustal types. Velocities of oceanic layer 3 (6.7 -7.1 km/s), transitional (7.2-7.6 km/s) and continental crust (5.5-6.6 km/s) were used to distinguish crustal types. Potential field data supports the distribution of oceanic crust as a polygon with maximum dimensions of ~340 km (east-west) by ~590 km (north-south) and identification of the ocean-continent boundary (OCB). Paired magnetic anomalies are associated only with crust that has oceanic velocities. Furthermore, the interpreted top of oceanic crust on seismic reflection profiles is more irregular and sometimes shallower than adjacent transitional crust. The northern segment of the narrow Canada Basin Gravity Low (CBGL), often interpreted as a spreading centre, bisects this zone of oceanic crust and coincides with the location of a prominent valley in seismic reflection profiles. Data coverage near the southern segment of CBGL is sparse. Velocities typical of transitional crust are determined east of it. Extension in this region, close to the inferred pole of rotation, may have been amagmatic. Offshore Alaska is a wide zone of thinned continental crust up to 300 km across. Published longer offset refraction experiments in the Basin confirm the depth to Moho and the lack of oceanic layer 3 velocities. Further north, towards Alpha Ridge and along Northwind Ridge, transitional crust is interpreted to be underplated or intruded by magmatism related to the emplacement of the High Arctic Large Igneous Province (HALIP). Although a rotational plate tectonic model is consistent with the extent of the conjugate magnetic anomalies that occupy only a portion of Canada Basin, it does not explain the asymmetrical configuration of the oceanic crust in the deep water portion of Canada Basin, and the unequal distribution of transitional and continental crust around the basin.Funding for this work was provided through the Geological Survey of Canada as part of the Canada’s Extended Continental Slope (ECS) Program. Funding for this work was also provided in part through the U.S. Geological Survey as part of the U.S. ECS Project.2018-02-0
    • 

    corecore