471 research outputs found

    Markers of cardiac dysfunction in cognitive impairment and dementia

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    Markers of cardiac dysfunction such as amino terminal pro-brain natriuretic peptide (NTpro-BNP) and high sensitivity cardiac troponin T (hs-cTnT) may be associated with dementia. However, limited data exist on their association with either pre-dementia stages, that is, cognitive impairment no dementia (CIND), or the burden of cerebrovascular diseases (CeVD). We therefore, examined the association of these biomarkers of cardiac dysfunction with CeVD in both CIND and dementia. A case–control study, with cases recruited from memory clinics and controls from memory clinics and community. All subjects underwent collection of blood samples, neuropsychological assessment, and neuroimaging. Subjects were classified as CIND and dementia based on clinical criteria whilst significant CeVD was defined as the presence of cortical infarcts and/or more than 2 lacunes and/or confluent white matter lesions in two regions of brain on Age-Related White Matter Changes Scale. We included a total of 35 controls (mean age: 65.9 years), 78 CIND (mean age: 70.2 years) and 80 cases with dementia (mean age: 75.6 years). Plasma concentrations of hs-cTnT were associated significantly with CeVD in both CIND (odds ratios [OR]: 9.05; 95% confidence interval [CI]: 1.64–49.79) and dementia (OR: 16.89; 95%CI: 2.02–142.67). In addition, NTpro-BNP was associated with dementia with CeVD (OR: 7.74; 95%CI: 1.23–48.58). These associations were independent of other vascular risk factors. In this study, we showed that plasma NTproBNP and hs-cTnT are associated with dementia and CIND, only when accompanied by presence of CeVD

    L\'evy-stable two-pion Bose-Einstein correlations in sNN=200\sqrt{s_{_{NN}}}=200 GeV Au++Au collisions

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    We present a detailed measurement of charged two-pion correlation functions in 0%-30% centrality sNN=200\sqrt{s_{_{NN}}}=200 GeV Au++Au collisions by the PHENIX experiment at the Relativistic Heavy Ion Collider. The data are well described by Bose-Einstein correlation functions stemming from L\'evy-stable source distributions. Using a fine transverse momentum binning, we extract the correlation strength parameter λ\lambda, the L\'evy index of stability α\alpha and the L\'evy length scale parameter RR as a function of average transverse mass of the pair mTm_T. We find that the positively and the negatively charged pion pairs yield consistent results, and their correlation functions are represented, within uncertainties, by the same L\'evy-stable source functions. The λ(mT)\lambda(m_T) measurements indicate a decrease of the strength of the correlations at low mTm_T. The L\'evy length scale parameter R(mT)R(m_T) decreases with increasing mTm_T, following a hydrodynamically predicted type of scaling behavior. The values of the L\'evy index of stability α\alpha are found to be significantly lower than the Gaussian case of α=2\alpha=2, but also significantly larger than the conjectured value that may characterize the critical point of a second-order quark-hadron phase transition.Comment: 448 authors, 25 pages, 11 figures, 4 tables, 2010 data. v2 is version accepted for publication in Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Inorganic-Organic Hybrid Nanomaterials for Therapeutic and Diagnostic Imaging Applications

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    Nanotechnology offers outstanding potential for future biomedical applications. In particular, due to their unique characteristics, hybrid nanomaterials have recently been investigated as promising platforms for imaging and therapeutic applications. This class of nanoparticles can not only retain valuable features of both inorganic and organic moieties, but also provides the ability to systematically modify the properties of the hybrid material through the combination of functional elements. Moreover, the conjugation of targeting moieties on the surface of these nanomaterials gives them specific targeted imaging and therapeutic properties. In this review, we summarize the recent reports in the synthesis of hybrid nanomaterials and their applications in biomedical areas. Their applications as imaging and therapeutic agents in vivo will be highlighted

    J/psi suppression at forward rapidity in Au+Au collisions at sqrt(s_NN)=39 and 62.4 GeV

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    We present measurements of the J/psi invariant yields in sqrt(s_NN)=39 and 62.4 GeV Au+Au collisions at forward rapidity (1.2<|y|<2.2). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au+Au collisions (R_CP) and for various centrality selections in Au+Au relative to scaled p+p cross sections obtained from other measurements (R_AA). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement.Comment: 365 authors, 10 pages, 11 figures, 4 tables. Submitted to Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Nuclear matter effects on J/ψJ/\psi production in asymmetric Cu+Au collisions at sNN\sqrt{s_{_{NN}}} = 200 GeV

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    We report on J/ψJ/\psi production from asymmetric Cu+Au heavy-ion collisions at sNN\sqrt{s_{_{NN}}}=200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/ψJ/\psi yields in Cu++Au collisions in the Au-going direction is found to be comparable to that in Au++Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/ψJ/\psi production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-xx gluon suppression in the larger Au nucleus. The relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.Comment: 349 authors, 10 pages, 4 figures, and 4 tables. Submitted to Phys. Rev. C. For v2, fixed LaTeX error in 3rd-to-last sentence. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Inclusive cross section and double-helicity asymmetry for π0\pi^{0} production at midrapidity in pp++pp collisions at s=510\sqrt{s}=510 GeV

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    PHENIX measurements are presented for the cross section and double-helicity asymmetry (ALLA_{LL}) in inclusive π0\pi^0 production at midrapidity from pp++pp collisions at s=510\sqrt{s}=510~GeV from data taken in 2012 and 2013 at the Relativistic Heavy Ion Collider. The next-to-leading-order perturbative-quantum-chromodynamics theory calculation is in excellent agreement with the presented cross section results. The calculation utilized parton-to-pion fragmentation functions from the recent DSS14 global analysis, which prefer a smaller gluon-to-pion fragmentation function. The π0ALL\pi^{0}A_{LL} results follow an increasingly positive asymmetry trend with pTp_T and s\sqrt{s} with respect to the predictions and are in excellent agreement with the latest global analysis results. This analysis incorporated earlier results on π0\pi^0 and jet ALLA_{LL}, and suggested a positive contribution of gluon polarization to the spin of the proton ΔG\Delta G for the gluon momentum fraction range x>0.05x>0.05. The data presented here extend to a currently unexplored region, down to x0.01x\sim0.01, and thus provide additional constraints on the value of ΔG\Delta G. The results confirm the evidence for nonzero ΔG\Delta G using a different production channel in a complementary kinematic region.Comment: 413 authors, 8 pages, 4 figures. v2 is version accepted as PRD Rapid Communication. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Measurement of higher cumulants of net-charge multiplicity distributions in Au++Au collisions at sNN=7.7200\sqrt{s_{_{NN}}}=7.7-200 GeV

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    We report the measurement of cumulants (Cn,n=14C_n, n=1\ldots4) of the net-charge distributions measured within pseudorapidity (η<0.35|\eta|<0.35) in Au++Au collisions at sNN=7.7200\sqrt{s_{_{NN}}}=7.7-200 GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g. C1/C2C_1/C_2, C3/C1C_3/C_1) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmonotonic behavior in the ratios of the cumulants as a function of collision energy. The measured values of C1/C2=μ/σ2C_1/C_2 = \mu/\sigma^2 and C3/C1=Sσ3/μC_3/C_1 = S\sigma^3/\mu can be directly compared to lattice quantum-chromodynamics calculations and thus allow extraction of both the chemical freeze-out temperature and the baryon chemical potential at each center-of-mass energy.Comment: 512 authors, 8 pages, 4 figures, 1 table. v2 is version accepted for publication in Phys. Rev. C as a Rapid Communication. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Medium modification of jet fragmentation in Au+Au collisions at sqrt(s_NN)=200 GeV measured in direct photon-hadron correlations

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    The jet fragmentation function is measured with direct photon-hadron correlations in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV. The p_T of the photon is an excellent approximation to the initial p_T of the jet and the ratio z_T=p_T^h/p_T^\gamma is used as a proxy for the jet fragmentation function. A statistical subtraction is used to extract the direct photon-hadron yields in Au+Au collisions while a photon isolation cut is applied in p+p. I_ AA, the ratio of jet fragment yield in Au+Au to that in p+p, indicates modification of the jet fragmentation function. Suppression, most likely due to energy loss in the medium, is seen at high z_T. The fragment yield at low z_T is enhanced at large angles. Such a trend is expected from redistribution of the lost energy into increased production of low-momentum particles.Comment: 562 authors, 70 insitutions, 8 pages, and 3 figures. Submitted to Phys. Rev. Lett. v2 has minor changes to improve clarity. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
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