43 research outputs found

    Compression of klockmannite, CuSe

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    Copper selenide (CuSe) was compressed in a diamond anvil cell at room temperature up to a pressure of 52 GPa and studied using energy dispersive x-ray diffraction and Raman spectroscopy. CuSe is nearly isostructural with copper sulfide (CuS), and a previous study indicates that copper sulfide undergoes reversible pressure-induced amorphization at 18 GPa. The intensity of the x-ray diffraction peaks for CuSe decrease slowly, however, they never completely disappear up to a pressure of 52 GPa. The third-order Birch–Murnaghan equation of state fit to the data yields K0 = 96.9±5.3 GPaK0=96.9±5.3GPa and K0â€Č = 4.1±0.5.K0â€Č=4.1±0.5. Vinet’s universal equation of state yields essentially identical parameters. Raman spectroscopy demonstrates that upon compression, the S–S bond in CuS compresses differently than the Se–Se bond in CuSe, possibly accounting for the different high pressure behavior of these two very similar compounds. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70875/2/JCPSA6-109-2-634-1.pd

    The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

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    Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

    A História da Alimentação: balizas historiogråficas

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    Os M. pretenderam traçar um quadro da HistĂłria da Alimentação, nĂŁo como um novo ramo epistemolĂłgico da disciplina, mas como um campo em desenvolvimento de prĂĄticas e atividades especializadas, incluindo pesquisa, formação, publicaçÔes, associaçÔes, encontros acadĂȘmicos, etc. Um breve relato das condiçÔes em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biolĂłgica, a econĂŽmica, a social, a cultural e a filosĂłfica!, assim como da identificação das contribuiçÔes mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histĂłrica, foi ela organizada segundo critĂ©rios morfolĂłgicos. A seguir, alguns tĂłpicos importantes mereceram tratamento Ă  parte: a fome, o alimento e o domĂ­nio religioso, as descobertas europĂ©ias e a difusĂŁo mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rĂĄpido balanço crĂ­tico da historiografia brasileira sobre o tema

    High-pressure phase behavior and equations of state of ThO_2 polymorphs

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    ThO_2 is an important material for understanding the heat budget of Earth's mantle, as well as the stability of nuclear fuels at extreme conditions. We measured the in situ high-pressure, high-temperature phase behavior of ThO_2 to ∌60 GPa and ∌2500 K. It undergoes a transition from the cubic fluorite-type structure (thorianite) to the orthorhombic α-PbCl_2 cotunnite-type structure between 20 and 30 GPa at room temperature. Prior to the transition at room temperature, an increase in unit-cell volume is observed, which we interpret as anion sub-lattice disorder or pre-transformation “melting” (Boulfelfel et al. 2006). The thermal equation of state parameters for both thorianite [V_0 = 26.379(7), K_0 = 204(2), αK_T = 0.0035(3)] and the high-pressure cotunnite-type phase [V_0 = 24.75(6), K_0 = 190(3), αK_T = 0.0037(4)] are reported, holding K_0â€Č fixed at 4. The similarity of these parameters suggests that the two phases behave similarly within the deep Earth. The lattice parameter ratios for the cotunnite-type phase change significantly with pressure, suggesting a different structure is stable at higher pressure

    High-pressure phase behavior and equations of state of ThO2 polymorphs

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    ThO2 is an important material for understanding the heat budget of Earth's mantle, as well as the stability of nuclear fuels at extreme conditions. We measured the in situ high-pressure, high-temperature phase behavior of ThO2 to similar to 60 GPa and similar to 2500 K. It undergoes a transition from the cubic fluorite-type structure (thorianite) to the orthorhombic alpha-PbCl2 cotunnite-type structure between 20 and 30 GPa at room temperature. Prior to the transition at room temperature, an increase in unit-cell volume is observed, which we interpret as anion sub-lattice disorder or pre-transformation melting (Boulfelfel et al. 2006). The thermal equation of state parameters for both thorianite [V-0 = 26.379(7), K-0 = 204(2), alpha K-T = 0.0035(3)] and the high-pressure cotunnite-type phase [V-0 = 24.75(6), K-0 = 190(3), alpha K-T = 0.0037(4)] are reported, holding K-0(') fixed at 4. The similarity of these parameters suggests that the two phases behave similarly within the deep Earth. The lattice parameter ratios for the cotunnite-type phase change significantly with pressure, suggesting a different structure is stable at higher pressure

    GolP-CHARMM : first-principles based force fields for the interaction of proteins with Au(111) and Au(100)

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    Computational simulation of peptide adsorption at the aqueous gold interface is key to advancing the development of many applications based on gold nanoparticles, ranging from nanomedical devices to smart biomimetic materials. Here, we present a force field, GolP-CHARMM, designed to capture peptide adsorption at both the aqueous Au(111) and Au(100) interfaces. The force field, compatible with the bio-organic force field CHARMM, is parametrized using a combination of experimental and first-principles data. Like its predecessor, GolP (Iori, F.; et al. J. Comput. Chem.2009, 30, 1465), this force field contains terms to describe the dynamic polarization of gold atoms, chemisorbing species, and the interaction between sp2 hybridized carbon atoms and gold. A systematic study of small molecule adsorption at both surfaces using the vdW-DF functional (Dion, M.; et al. Phys. Rev. Lett.2004, 92, 246401–1. Thonhauser, T.; et al. Phys. Rev. B2007, 76, 125112) is carried out to fit and test force field parameters and also, for the first time, gives unique insights into facet selectivity of gold binding in vacuo. Energetic and spatial trends observed in our DFT calculations are reproduced by the force field under the same conditions. Finally, we use the new force field to calculate adsorption energies, under aqueous conditions, for a representative set of amino acids. These data are found to agree with experimental findings

    How Big Is a Policy Network? An Assessment Utilizing Data From Canadian Royal Commissions 1970-2000

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    The subsystem approach to policy studies is now well established in theory. Despite many applications to empirical cases, however, many elements of the operationalization of this approach have remained problematic, prompting some critics to reject it as "unscientific." Although the approach has been defended as "more than a metaphor," it is certainly apparent that additional work is required to address fundamental aspects of the model and ensure that its application to specific cases is done in such a way as to meet basic methodological prerequisites of consistency and replication. This article builds on earlier work by one of the authors attempting to address some of these concerns. Specifically, it addresses issues surrounding the methods through which subsystem membership can be identified and attempts some preliminary conclusions with respect to the estimation of average subsystem size in contemporary advanced liberal democracies. Copyright 2006 by The Policy Studies Organization.
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