9,914 research outputs found

    Metabolism of ticagrelor in patients with acute coronary syndromes.

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    © The Author(s) 2018Ticagrelor is a state-of-the-art antiplatelet agent used for the treatment of patients with acute coronary syndromes (ACS). Unlike remaining oral P2Y12 receptor inhibitors ticagrelor does not require metabolic activation to exert its antiplatelet action. Still, ticagrelor is extensively metabolized by hepatic CYP3A enzymes, and AR-C124910XX is its only active metabolite. A post hoc analysis of patient-level (n = 117) pharmacokinetic data pooled from two prospective studies was performed to identify clinical characteristics affecting the degree of AR-C124910XX formation during the first six hours after 180 mg ticagrelor loading dose in the setting of ACS. Both linear and multiple regression analyses indicated that ACS patients presenting with ST-elevation myocardial infarction or suffering from diabetes mellitus are more likely to have decreased rate of ticagrelor metabolism during the acute phase of ACS. Administration of morphine during ACS was found to negatively influence transformation of ticagrelor into AR-C124910XX when assessed with linear regression analysis, but not with multiple regression analysis. On the other hand, smoking appears to increase the degree of ticagrelor transformation in ACS patients. Mechanisms underlying our findings and their clinical significance warrant further research.Peer reviewedFinal Published versio

    Grown-in defects and defects produced by 1-Me electron irradiated in Al0.3Ga0.7As P-N junction solar cells

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    Studies of grown-in defects and defects produced by the one-MeV electron irradiation in Al sub 0.3 Ga sub 0.7As p-n junction solar cells fabricated by liquid phase epitaxial (LPE) technique were made for the unirradiated and one-MeV electron irradiated samples, using DLTS and C-V methods. Defect and recombination parameters such as energy level, defect density, carrier capture cross sections and lifetimes were determined for various growth, annealing, and irradiation conditions

    First order magnetic transition in CeFe2_2 alloys: Phase-coexistence and metastability

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    First order ferromagnetic (FM) to antiferromagnetic (AFM) phase transition in doped-CeFe2_2 alloys is studied with micro-Hall probe technique. Clear visual evidence of magnetic phase-coexistence on micrometer scales and the evolution of this phase-coexistence as a function of temperature, magnetic field and time across the first order FM-AFM transition is presented. Such phase-coexistence and metastability arise as natural consequence of an intrinsic disorder-influenced first order transition. Generality of this phenomena involving other classes of materials is discussed.Comment: 11 pages of text and 3 figure

    Autochthony and isotopic niches of benthic fauna at shallow-water hydrothermal vents

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    The food webs of shallow-water hydrothermal vents are supported by chemosynthetic and photosynthetic autotrophs. However, the relative importance of these two basal resources for benthic consumers and its changes along the physicochemical gradient caused by vent plumes are unknown. We used stable carbon and nitrogen isotopes (i.e., delta C-13 and delta N-15) and Bayesian mixing models to quantify the dietary contribution of basal resources to the benthic fauna at the shallow-water vents around Kueishan Island, Taiwan. Our results indicated that the food chains and consumer production at the shallow-water vents were mainly driven by photoautotrophs (total algal contribution: 26-54%) and zooplankton (19-34%) rather than by chemosynthetic production (total contribution: 14-26%). Intraspecific differences in the trophic support and isotopic niche of the benthic consumers along the physicochemical gradient were also evident. For instance, sea anemone Anthopleura sp. exhibited the greatest reliance on chemosynthetic bacteria (26%) and photoautotrophs (66%) near the vent openings, but zooplankton was its main diet in regions 150-300 m (32-49%) and 300-700 m (32-78%) away from the vent mouths. The vent-induced physicochemical gradient structures not only the community but also the trophic support and isotopic niche of vent consumers

    HA-grid: security aware hazard analysis for smart grids

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    Attacks targeting smart grid infrastructures can result in the disruptions of power supply as well as damages to costly equipment, with significant impact on safety as well as on end-consumers. It is therefore of essence to identify attack paths in the infrastructure that lead to safety violations and to determine critical components that must be protected. In this paper, we introduce a methodology (HA-Grid) that incorporates both safety and security modelling of smart grid infrastructure to analyse the impact of cyber threats on the safety of smart grid infrastructures. HA-Grid is applied on a smart grid test-bed to identify attack paths that lead to safety hazards, and to determine the common nodes in these attack paths as critical components that must be protected

    Search for the Lepton-Number-Violating Decay Ξpμμ\Xi^- \to p \mu^- \mu^-

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    A sensitive search for the lepton-number-violating decay Ξpμμ\Xi^-\to p \mu^-\mu^- has been performed using a sample of 109\sim10^9 Ξ\Xi^- hyperons produced in 800 GeV/cc pp-Cu collisions. We obtain B(Ξpμμ)<4.0×108\mathcal{B}(\Xi^-\to p \mu^-\mu^-)< 4.0\times 10^{-8} at 90% confidence, improving on the best previous limit by four orders of magnitude.Comment: 9 pages, 5 figures, to be published in Phys. Rev. Let

    The derivation of performance expressions for communication protocols from timed Petri net models

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    Petri Net models have been extended in a variety of ways and have been used to prove the correctness and evaluate the performance of communication protocols. Several extensions have been proposed to model time. This work uses a form of Timed Petri Nets and presents a technique for symbolically deriving expressions which describe system performance. Unlike past work on performance evaluation of Petri Nets which assumes a priori knowledge of specific time delays, the technique presented here applies to a wide range of time delays so long as the delays satisfy a set of timing constraints. The technique is demonstrated using a simple communication protocol

    BI~DIVERSITY AND SUSTAINABILITY OF WETLAND RICE PRODUCTION: I ROLE AND POTENTIAL OF MICROORGANISMS AND INVERTEBRATES I

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    Summary This review considers some of the ecological foundations of sustainable wetland rice production related to microorganisms and invertebrates and their biodiversity. It summarizes (1) the aspects of sustainability of rice-producing environments involving microbial and invertebrate populations --maintenance of soil fertility, effects and control of rice pests and vector-borne diseases-&quot;, (2) how factors of crop intensification affect these populations and their biodiversity, (3) the agricultural practices that use microbial and invertebrate populations and their biodiversity, and (4) the current status of germplasm collections and the potential of biotechnology to use them to improve the sustainability of rice-producing environments. production have been identified and, sometimes, quantified. However, less is known about the possible long-term effects of crop intensification on these populations and their biodiversity. control pests and diseases have been tested. But the success of these methods is limited and their adoption almost negligible. This situation will probably remain unchanged as long as the methods designed are based on a very restricted knowledge on biodiversity, community structure, and trophic relationships at the ecosystem level, as it is currently. pest populations. Increases in pest and vector densities depend more on predator diversity, species resilience to perturbations, and biological attributes. Thus, increasing or preserving diversity per se does not necessarily contribute to pest stability, but developing effective trophic linkage
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