279 research outputs found
Tunneling spectra of submicron BiSrCaCuO intrinsic Josephson junctions: evolution from superconducting gap to pseudogap
Tunneling spectra of near optimally doped, submicron
BiSrCaCuO intrinsic Josephson junctions are presented,
and examined in the region where the superconducting gap evolves into
pseudogap. The spectra are analyzed using a self-energy model, proposed by
Norman {\it et al.}, in which both quasiparticle scattering rate and
pair decay rate are considered. The density of states derived
from the model has the familiar Dynes' form with a simple replacement of
by = ( + )/2. The
parameter obtained from fitting the experimental spectra shows a roughly linear
temperature dependence, which puts a strong constraint on the relation between
and . We discuss and compare the Fermi arc behavior
in the pseudogap phase from the tunneling and angle-resolved photoemission
spectroscopy experiments. Our results indicate an excellent agreement between
the two experiments, which is in favor of the precursor pairing view of the
pseudogap.Comment: 7 pages, 6 figure
Symmetric-Asymmetric transition in mixtures of Bose-Einstein condensates
We propose a new kind of quantum phase transition in phase separated mixtures
of Bose-Einstein condensates. In this transition, the distribution of the two
components changes from a symmetric to an asymmetric shape. We discuss the
nature of the phase transition, the role of interface tension and the phase
diagram. The symmetric to asymmetric transition is the simplest quantum phase
transition that one can imagine. Careful study of this problem should provide
us new insight into this burgeoning field of discovery.Comment: 6 pages, 3 eps figure
A proteomics-based assessment of inflammation signatures in endotoxemia
We have previously shown that multimers of plasma pentraxin-3 (PTX3) were predictive of survival in patients with sepsis. To characterize the release kinetics and cellular source of plasma protein changes in sepsis, serial samples were obtained from healthy volunteers (n = 10; three time points) injected with low-dose endotoxin (lipopolysaccharide [LPS]) and analyzed using data-independent acquisition MS. The human plasma proteome response was compared with an LPS-induced endotoxemia model in mice. Proteomic analysis of human plasma revealed a rapid neutrophil degranulation signature, followed by a rise in acute phase proteins. Changes in circulating PTX3 correlated with increases in neutrophil-derived proteins following LPS injection. Time course analysis of the plasma proteome in mice showed a time-dependent increase in multimeric PTX3, alongside increases in neutrophil-derived myeloperoxidase (MPO) upon LPS treatment. The mechanisms of oxidation-induced multimerization of PTX3 were explored in two genetic mouse models: MPO global knock-out (KO) mice and LysM Cre Nox2 KO mice, in which NADPH oxidase 2 (Nox2) is only deficient in myeloid cells. Nox2 is the enzyme responsible for the oxidative burst in neutrophils. Increases in plasma multimeric PTX3 were not significantly different between wildtype and MPO or LysM Cre Nox2 KO mice. Thus, PTX3 may already be stored and released in a multimeric form. Through in vivo neutrophil depletion and multiplexed vascular proteomics, PTX3 multimer deposition within the aorta was confirmed to be neutrophil dependent. Proteomic analysis of aortas from LPS-injected mice returned PTX3 as the most upregulated protein, where multimeric PTX3 was deposited as early as 2 h post-LPS along with other neutrophil-derived proteins. In conclusion, the rise in multimeric PTX3 upon LPS injection correlates with neutrophil-related protein changes in plasma and aortas. MPO and myeloid Nox2 are not required for the multimerization of PTX3; instead, neutrophil extravasation is responsible for the LPS-induced deposition of multimeric PTX3 in the aorta
Study of two dose regimens of ticagrelor compared with clopidogrel in patients undergoing percutaneous coronary intervention for stable coronary artery disease
Background—Ticagrelor has superior efficacy to clopidogrel in the management of acute coronary syndromes but has not been assessed in patients undergoing percutaneous coronary intervention (PCI) for stable coronary artery disease (CAD). We compared the pharmacodynamic effects of ticagrelor and clopidogrel in this stable population.
Methods—180 aspirin-treated stable CAD patients, who were planned to undergo elective PCI in a single center, were randomized 1:1:1 to either a standard clopidogrel regimen or one of two regimens of ticagrelor, either 90mg (T90) or 60mg twice-daily (T60), both with 180mg loading dose. Cellular adenosine uptake was assessed, at the time of the procedure and pre- and post-dose at 1 month, by adding adenosine 1 μmol/L to aliquots of anticoagulated whole blood and mixing with a stop solution at 0, 15, 30 and 60 seconds then measuring residual plasma adenosine concentration by high-performance liquid chromatography. Systemic plasma adenosine concentration and platelet reactivity were assessed at the same timepoints. High-sensitivity troponin T (hsTnT) was measured pre- and 18-24 hours post-PCI.
Results—174 patients underwent an invasive procedure, of which 162 patients received PCI (mean age 65 years, 18% female, 21% with diabetes mellitus). No effect on in vitro adenosine uptake was seen post-dose at 1 month for either ticagrelor dose compared with clopidogrel (residual adenosine at 15s, mean ± SD: clopidogrel 0.274 ± 0.101 μmol/L; T90 0.278 ± 0.134 μmol/L; T60 0.288 ± 0.149 μmol/L; P = 0.37). Similarly no effect of ticagrelor on in vitro adenosine uptake was seen at other timepoints, nor was plasma adenosine concentration affected (all P > 0.1). Both maintenance doses of ticagrelor achieved more potent and consistent platelet inhibition than clopidogrel (VerifyNow PRU, 1 month, mean ± SD: pre-dose, T60: 62 ± 47, T90: 40 ± 38, clopidogrel 181 ± 44; post-dose, T60: 34 ± 30, T90: 24 ± 21, clopidogrel 159 ± 57; all P 208, 1-month post-dose: 0%, 0% and 21%, respectively). Median (IQR) hsTnT increase was 16.9 (6.5-46.9) ng/l for clopidogrel, 22.4 (5.5-53.8) ng/L for T60 and 17.7 (8.1-43.5) ng/L for T90 (P = 0.95). There was a trend towards less dyspnea with T60 versus T90 (7.1% vs 19.0%; P = 0.09).
Conclusions—Maintenance therapy with T60 or T90 had no detectable effect on cellular adenosine uptake at 1 month, nor was there any effect on systemic plasma adenosine levels. Both regimens of ticagrelor achieved greater and more consistent platelet inhibition than clopidogrel but did not appear to affect troponin release after percutaneous coronary interventio
Fitting the integrated Spectral Energy Distributions of Galaxies
Fitting the spectral energy distributions (SEDs) of galaxies is an almost
universally used technique that has matured significantly in the last decade.
Model predictions and fitting procedures have improved significantly over this
time, attempting to keep up with the vastly increased volume and quality of
available data. We review here the field of SED fitting, describing the
modelling of ultraviolet to infrared galaxy SEDs, the creation of
multiwavelength data sets, and the methods used to fit model SEDs to observed
galaxy data sets. We touch upon the achievements and challenges in the major
ingredients of SED fitting, with a special emphasis on describing the interplay
between the quality of the available data, the quality of the available models,
and the best fitting technique to use in order to obtain a realistic
measurement as well as realistic uncertainties. We conclude that SED fitting
can be used effectively to derive a range of physical properties of galaxies,
such as redshift, stellar masses, star formation rates, dust masses, and
metallicities, with care taken not to over-interpret the available data. Yet
there still exist many issues such as estimating the age of the oldest stars in
a galaxy, finer details ofdust properties and dust-star geometry, and the
influences of poorly understood, luminous stellar types and phases. The
challenge for the coming years will be to improve both the models and the
observational data sets to resolve these uncertainties. The present review will
be made available on an interactive, moderated web page (sedfitting.org), where
the community can access and change the text. The intention is to expand the
text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics &
Space Scienc
Cichlid biogeography: comment and review
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72313/1/j.1467-2979.2004.00148.x.pd
The Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a second generation water Cherenkov
detector designed to determine whether the currently observed solar neutrino
deficit is a result of neutrino oscillations. The detector is unique in its use
of D2O as a detection medium, permitting it to make a solar model-independent
test of the neutrino oscillation hypothesis by comparison of the charged- and
neutral-current interaction rates. In this paper the physical properties,
construction, and preliminary operation of the Sudbury Neutrino Observatory are
described. Data and predicted operating parameters are provided whenever
possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and
epsf style files. For additional information about SNO see
http://www.sno.phy.queensu.ca . This version has some new reference
Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV
Peer reviewe
Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV
Peer reviewe
Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV
Peer reviewe
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