15,517 research outputs found
Metabolism of ticagrelor in patients with acute coronary syndromes.
© 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
N=2 and N=4 SUSY Yang-Mills action on M x (Z + Z) non-commutative geometry
We show that the N=2 and N=4 SUSY Yang-Mills action can be reformulated in the sense of non-commutative geometry on M^4\times (Z_2\oplus Z_2) in a rather simple way. In this way the scalars or pseudoscalars are viewed as gauge fields along two directions in the space of one-forms on Z_2\oplus Z_2
Pseudomagnetic Fields in a Locally Strained Graphene Drumhead
Recent experiments reveal that a scanning tunneling microscopy (STM) probe
tip can generate a highly localized strain field in a graphene drumhead, which
in turn leads to pseudomagnetic fields in the graphene that can spatially
confine graphene charge carriers in a way similar to a lithographically defined
quantum dot (QD). While these experimental findings are intriguing, their
further implementation in nanoelectronic devices hinges upon the knowledge of
key underpinning parameters, which still remain elusive. In this paper, we
first summarize the experimental measurements of the deformation of graphene
membranes due to interactions with the STM probe tip and a back gate electrode.
We then carry out systematic coarse grained, (CG), simulations to offer a
mechanistic interpretation of STM tip-induced straining of the graphene
drumhead. Our findings reveal the effect of (i) the position of the STM probe
tip relative to the graphene drumhead center, (ii) the sizes of both the STM
probe tip and graphene drumhead, as well as (iii) the applied back-gate
voltage, on the induced strain field and corresponding pseudomagnetic field.
These results can offer quantitative guidance for future design and
implementation of reversible and on-demand formation of graphene QDs in
nanoelectronics.Comment: 21 pages, 9 figure
Inequalities Detecting Quantum Entanglement for Systems
We present a set of inequalities for detecting quantum entanglement of
quantum states. For and systems, the
inequalities give rise to sufficient and necessary separability conditions for
both pure and mixed states. For the case of , these inequalities are
necessary conditions for separability, which detect all entangled states that
are not positive under partial transposition and even some entangled states
with positive partial transposition. These inequalities are given by mean
values of local observables and present an experimental way of detecting the
quantum entanglement of quantum states and even multi-qubit pure
states.Comment: 6 page
A Chandra X-Ray Survey of Ultraluminous Infrared Galaxies
We present results from Chandra observations of 14 ultraluminous infrared
galaxies (ULIRGs; log(L_IR/L_Sun) >= 12) with redshifts between 0.04 and 0.16.
The goals of the observations were to investigate any correlation between
infrared color or luminosity and the properties of the X-ray emission and to
attempt to determine whether these objects are powered by starbursts or active
galactic nuclei (AGNs). The sample contains approximately the same number of
high and low luminosity objects and ``warm'' and ``cool'' ULIRGs. All 14
galaxies were detected by Chandra. Our analysis shows that the X-ray emission
of the two Seyfert 1 galaxies in our sample are dominated by AGN. The remaining
12 sources are too faint for conventional spectral fitting to be applicable.
Hardness ratios were used to estimate the spectral properties of these faint
sources. The photon indices for our sample plus the Chandra-observed sample
from Ptak et al.(2003) peak in the range of 1.0-1.5, consistent with
expectations for X-ray binaries in a starburst, an absorbed AGN, or hot
bremsstrahlung from a starburst or AGN. The values of photon index for the
objects in our sample classified as Seyferts (type 1 or 2) are larger than 2,
while those classified as HII regions or LINERs tend to be less than 2. The
hard X-ray to far-infrared ratios for the 12 weak sources are similar to those
of starbursts, but we cannot rule out the possibility of absorbed, possibly
Compton-thick, AGNs in some of these objects. Two of these faint sources were
found to have X-ray counterparts to their double optical and infrared nuclei.Comment: 40 pages, 5 tables, 14 figures, accepted by Ap
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