1,040 research outputs found
Gluon Saturation Effects in Relativistic U+U Collisions
We examine entropy production in relativistic U+U collisions on the basis of
a Color Glass Condensate (CGC) type picture as implemented in the
Kharzeev-Levin-Nardi model (KLN). In this framework, we find that the peak
entropy density produced in tip-on-tip U+U collisions is about 30% greater than
that seen in central Au+Au collisions. Although the resulting difference in the
produced charged particle multiplicity between tip-on-tip and side-on-side
collisions is smaller than that predicted by previous Glauber model estimates,
it is still large enough to allow for experimental discrimination between
average orientations of the uranium nuclei. We also point out that in the
saturation/CGC approach the collision geometry plays a more important role than
previously believed, and that the observed centrality dependence of the
produced particle multiplicity per participant in Au+Au collisions can be
qualitatively reproduced even without running coupling effects.Comment: 7 pages, including 8 figure
An organotypic slice culture model of chronic white matter injury with maturation arrest of oligodendrocyte progenitors
<p>Abstract</p> <p>Background</p> <p>CNS myelination disturbances commonly occur in chronic white matter lesions in neurodevelopmental and adult neurological disorders. Recent studies support that myelination failure can involve a disrupted cellular repair mechanism where oligodendrocyte (OL) progenitor cells (OPCs) proliferate in lesions with diffuse astrogliosis, but fail to fully differentiate to mature myelinating OLs. There are no <it>in vitro </it>models that reproduce these features of myelination failure.</p> <p>Results</p> <p>Forebrain coronal slices from postnatal day (P) 0.5/1 rat pups were cultured for 1, 5, or 9 days <it>in vitro </it>(DIV). Slices rapidly exhibited diffuse astrogliosis and accumulation of the extracellular matrix glycosaminoglycan hyaluronan (HA), an inhibitor of OPC differentiation and re-myelination. At 1 DIV ~1.5% of Olig2<sup>+ </sup>OLs displayed caspase-3 activation, which increased to ~11.5% by 9 DIV. At 1 DIV the density of PDGFRα<sup>+ </sup>and PDGFRα<sup>+</sup>/Ki67<sup>+ </sup>OPCs were significantly elevated compared to 0 DIV (<it>P </it>< 0.01). Despite this proliferative response, at 9 DIV ~60% of white matter OLs were late progenitors (preOLs), compared to ~7% in the postnatal day 10 rat (<it>P </it>< 0.0001), consistent with preOL maturation arrest. Addition of HA to slices significantly decreased the density of MBP<sup>+ </sup>OLs at 9 DIV compared to controls (217 ± 16 <it>vs. </it>328 ± 17 cells/mm<sup>2</sup>, respectively; <it>P </it>= 0.0003), supporting an inhibitory role of HA in OL lineage progression in chronic lesions.</p> <p>Conclusions</p> <p>Diffuse white matter astrogliosis and early OPC proliferation with impaired OL maturation were reproduced in this model of myelination failure. This system may be used to define mechanisms of OPC maturation arrest and myelination failure related to astrogliosis and HA accumulation.</p
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Physician communication styles in initial consultations for hematological cancer
Objective
To characterize practices in subspecialist physicians’ communication styles, and their potential effects on shared decision-making, in second-opinion consultations.
Methods
Theme-oriented discourse analysis of 20 second-opinion consultations with subspecialist hematologist-oncologists.
Results
Physicians frequently “broadcasted” information about the disease, treatment options, relevant research, and prognostic information in extended, often-uninterrupted monologues. Their communicative styles had one of two implications: conveying options without offering specific recommendations, or recommending one without incorporating patients’ goals and values into the decision. Some physicians, however, used techniques that encouraged patient participation.
Conclusions
Broadcasting may be a suboptimal method of conveying complex treatment information in order to support shared decision-making. Interventions could teach techniques that encourage patient participation.
Practice Implications
Techniques such as open-ended questions, affirmations of patients’ expressions, and pauses to check for patient understanding can mitigate the effects of broadcasting and could be used to promote shared decision-making in information-dense subspecialist consultations.Other Research Uni
The challenge of measuring intra-individual change in fatigue during cancer treatment
Evaluate how well three different patient-reported outcomes (PROs) measure individual change
Effect of alkyl chain length on the properties of triphenylamine-based hole transport materials and their performance in perovskite solar cells
A new series of diacetylide-triphenylamine (DATPA) derivatives with five different alkyl chains in the para position, MeO, EtO, nPrO, iPrO and BuO, were synthesised, fully characterised and their function as hole-transport materials in perovskite solar cells (PSC) studied. Their thermal, optical and electrochemical properties were investigated along with their molecular packing and charge transport properties to analyse the influence of different alkyl chains in the solar cell parameters. The shorter alkyl chain facilitates more compact packing structures which enhanced the hole mobilities and reduced recombination. This work suggests that the molecule with the methoxy substituent (MeO) exhibits the best semiconductive properties with a power conversion efficiency of up to 5.63%, an open circuit voltage (Voc) of 0.83 V, a photocurrent density (Jsc) of 10.84 mA cm−2 and a fill factor of 62.3% in perovskite solar cells. Upon replacing the methoxy group with longer alkyl chain substituents without changing the energy levels, there is a decrease in the charge mobility as well as PCE (e.g. 3.29% for BuO-DATPA). The alkyl chain length of semiconductive molecules plays an important role in achieving high performance perovskite solar cells
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
Winners, Losers, Insiders, and Outsiders: Comparing Hierometer and Sociometer Theories of Self-Regard.
What evolutionary function does self-regard serve? Hierometer theory, introduced here, provides one answer: it helps individuals navigate status hierarchies, which feature zero-sum contests that can be lost as well as won. In particular, self-regard tracks social status to regulate behavioral assertiveness, augmenting or diminishing it to optimize performance in such contests. Hierometer theory also offers a conceptual counterpoint that helps resolve ambiguities in sociometer theory, which offers a complementary account of self-regard's evolutionary function. In two large-scale cross-sectional studies, we operationalized theoretically relevant variables at three distinct levels of analysis, namely, social (relations: status, inclusion), psychological (self-regard: self-esteem, narcissism), and behavioral (strategy: assertiveness, affiliativeness). Correlational and mediational analyses consistently supported hierometer theory, but offered only mixed support for sociometer theory, including when controlling for confounding constructs (anxiety, depression). We interpret our results in terms of a broader agency-communion framework
Spreading depolarizations cycle around and enlarge focal ischaemic brain lesions
How does infarction in victims of stroke and other types of acute brain injury expand to its definitive size in subsequent days? Spontaneous depolarizations that repeatedly spread across the cerebral cortex, sometimes at remarkably regular intervals, occur in patients with all types of injury. Here, we show experimentally with in vivo real-time imaging that similar, spontaneous depolarizations cycle repeatedly around ischaemic lesions in the cerebral cortex, and enlarge the lesion in step with each cycle. This behaviour results in regular periodicity of depolarization when monitored at a single point in the lesion periphery. We present evidence from clinical monitoring to suggest that depolarizations may cycle in the ischaemic human brain, perhaps explaining progressive growth of infarction. Despite their apparent detrimental role in infarct growth, we argue that cycling of depolarizations around lesions might also initiate upregulation of the neurobiological responses involved in repair and remodelling
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