2,626 research outputs found

    Association between cognition and the retinal microvasculature in 11-year old children born preterm or at term

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    Background: Retinal microvessels can be visualized non-invasively and mirror the status of the cerebral microvasculature. Aims: To investigate whether in young children born prematurely or at term cognitive performance is related to retinal microvascular traits. Study design, subjects: In 93 prematurely born infants (birth weight < 1000 g) and 87 controls born at term, we measured head circumference (HC) and determined intelligence quotient (IQ) by combining matrix reasoning and spatial span (Wechsler Non-Verbal test, Dutch version) and post-processed retinal photographs using Singapore I Vessel Assessment software (version 3.6). Outcome measures, results: Compared with controls, cases had smaller HC (51.7 vs 53.4 cm; p < 0.001), lower IQ (93.9 vs 109.2; p < 0.001), smaller retinal arteriolar (CRAE; 162.7 vs 174.0 μm; p < 0.001) and venular (CRVE; 234.9 vs 242.8 μm; p = 0.003) diameters and CRAE/CRVE ratio (0.69 vs 0.72; p = 0.001). A 1-SD decrease in CRAE was associated with smaller HC (−0.53 cm; p < 0.001) and lower total IQ (−3.74; p < 0.001), matrix reasoning (−1.77; p = 0.004) and spatial span (−2.03; p = 0.002). These associations persisted after adjustment for sex and age and risk factors for cognitive impairment, including blood pressure, body mass index and parental educational attainment. Conclusions: HC, total IQ, matrix reasoning and spatial span decrease with smaller retinal arteriolar diameter. Our findings suggest that maldevelopment of the cerebral microcirculation, as mirrored by the retinal microvasculature, has lasting effects on the growth of the brain and cognitive performance of prematurely born children

    Conventional and ambulatory blood pressure as predictors of diastolic left ventricular function in a Flemish population

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    Background--No longitudinal study compared associations of echocardiographic indexes of diastolic left ventricular function studies with conventional (CBP) and daytime ambulatory (ABP) blood pressure in the general population. Methods and Results--In 780 Flemish (mean age, 50.2 years; 51.7% women), we measured left atrial volume index (LAVI), peak velocities of the transmitral blood flow (E) and mitral annular movement (e0) in early diastole and E/e0 9.6 years (median) after CBP and ABP. In adjusted models including CBP and ABP, we expressed associations per 10/5-mm Hg systolic/diastolic blood pressure increments. LAVI and E/e0 were 0.65/0.40 mL/m2 and 0.17/0.09 greater with higher systolic/diastolic ABP (P≤0.028), but not with higher baseline CBP (P≤0.086). e0 was lower (P≤0.032) with higher diastolic CBP (-0.09 cm/s) and ABP (-0.19 cm/s). When we substituted baseline CBP by CBP recorded concurrently with echocardiography, LAVI and E/e0 remained 0.45/0.38 mL/m2 and 0.15/0.08 greater with baseline ABP (P≤0.036), while LAVI (+0.53 mL/m2) and E/e0 (+0.19) were also greater (P < 0.001) in relation to concurrent systolic CBP. In categorized analyses of baseline data, sustained hypertension or masked hypertension compared with normotension or white-

    Partial Wave Analysis of χc0π+πK+K\chi_{c0}\to\pi^+\pi^-K^+K^-

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    A partial wave analysis of χc0π+πK+K\chi_{c0}\to\pi^+\pi^-K^+K^- in ψ(2S)γχc0\psi(2S)\to\gamma\chi_{c0} decay is presented using a sample of 14 million ψ(2S)\psi(2S) events accumulated by the BES II detector. The data are fitted to the sum of relativistic covariant tensor amplitudes for intermediate resonant decay modes. From the fit, significant contributions to χc0\chi_{c0} decays from the channels f0(980)f0(980)f_0(980)f_0(980), f0(980)f0(2200)f_0(980)f_0(2200), f0(1370)f0(1710)f_0(1370)f_0(1710), K(892)0Kˉ(892)0K^*(892)^0\bar K^*(892)^0, K0(1430)Kˉ0(1430)K^*_0(1430)\bar K^*_0(1430), K0(1430)Kˉ2(1430)+c.c.K^*_0(1430)\bar K^*_2(1430) + c.c., and K1(1270)KK_1(1270)K are found. Flavor-SU(3)-violating K1(1270)K1(1400)K_1(1270)-K_1(1400) asymmetry is observed. Values obtained for the masses and widths of the resonances f0(1710)f_0(1710), f0(2200)f_0(2200), f0(1370)f_0(1370), and K0(1430)K^*_0(1430) are presented.Comment: 16 pages, 9 figures, and 4 table

    Measurements of J/psi decays into phi pi^0, phi eta, and phi eta^prime

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    Based on 5.8x10^7 J/psi events detected in BESII, the branching fractions of J/psi--> phi eta and phi eta^prime are measured for different eta and eta^prime decay modes. The results are significantly higher than previous measurements. An upper limit on B(J/psi--> phi pi^0) is also obtained.Comment: 9 pages, 10 figure

    Observation of a resonance X(1835) in J/\psi --> \gamma \pi^+ \pi^- \eta^{\prime}

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    The decay channel J/\psi --> \gamma \pi^+ \pi^- \eta^{\prime} is analyzed using a sample of 5.8\times 10^7 J\psi events collected with the BESII detector. A resonance, the X(1835), is observed in the \pi^+ \pi^- \eta^{\prime} invariant mass spectrum with a statistical significance of 7.7 \sigma. A fit with a Breit-Wigner function yields a mass M = 1833.7 \pm 6.1(stat) \pm 2.7(syst) MeV/c^2, a width \Gamma = 67.7 \pm 20.3(stat) \pm 7.7(syst) MeV/c^2 and a product branching fraction B(J/\psi --> \gamma X) B(X --> \pi^+ \pi^- \eta^{\prime}) = (2.2 \pm 0.4(stat) \pm 0.4(syst)) \times 10^{-4}. The mass and width of the X(1835) are not compatible with any known meson resonance. Its properties are consistent with expectations for the state that produces the strong p\bar{p} mass threshold enhancement observed in the J\psi -->\gamma p \bar{p} process at BESII.Comment: 5 pages, 3 figures, RevTex4, Submitted to Phys. Rev. Let

    Measurement of the chi_{c2} Polarization in psi(2S) to gamma chi_{c2}

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    The polarization of the chi_{c2} produced in psi(2S) decays into gamma chi_{c2} is measured using a sample of 14*10^6 psi(2S) events collected by BESII at the BEPC. A fit to the chi_{c2} production and decay angular distributions in psi(2S) to gamma chi_{c2}, chi_{c2} to pi pi and KK yields values x=A_1/A_0=2.08+/-0.44 and y=A_2/A_0=3.03 +/-0.66, with a correlation rho=0.92 between them, where A_{0,1,2} are the chi_{c2} helicity amplitudes. The measurement agrees with a pure E1 transition, and M2 and E3 contributions do not differ significantly from zero.Comment: 6 pages, 4 figures, 1 tabl

    Measurement of the branching fractions of psi(2S) -> 3(pi+pi-) and J/psi -> 2(pi+pi-)

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    Using data samples collected at sqrt(s) = 3.686GeV and 3.650GeV by the BESII detector at the BEPC, the branching fraction of psi(2S) -> 3(pi+pi-) is measured to be [4.83 +- 0.38(stat) +- 0.69(syst)] x 10^-4, and the relative branching fraction of J/psi -> 2(pi+pi-) to that of J/psi -> mu+mu- is measured to be [5.86 +- 0.19(stat) +- 0.39(syst)]% via psi(2S) -> (pi+pi-)J/psi, J/psi -> 2(pi+pi-). The electromagnetic form factor of 3(pi+pi-) is determined to be 0.21 +- 0.02 and 0.20 +- 0.01 at sqrt(s) = 3.686GeV and 3.650GeV, respectively.Comment: 17pages, 7 figures, submitted to Phys. Rev.

    Search for psi(3770)\ra\rho\pi at the BESII detector at the Beijing Electron-Positron Collider

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    Non-DDˉD\bar{D} decay \psppto \rhopi is searched for using a data sample of (17.3±0.5)pb1(17.3\pm 0.5) pb^{-1} taken at the center-of-mass energy of 3.773 GeV by the BESII detector at the BEPC. No \rhopi signal is observed, and the upper limit of the cross section is measured to be \sigma(\EETO \rhopi)<6.0 pb at 90% C. L. Considering the interference between the continuum amplitude and the \pspp resonance amplitude, the branching fraction of \pspp decays to ρπ\rho\pi is determined to be \BR(\pspp\ra\rho\pi)\in(6.0\times10^{-6}, 2.4\times10^{-3}) at 90% C. L. This is in agreement with the prediction of the SS- and DD-wave mixing scheme of the charmonium states for solving the ``\rhopi puzzle'' between \jpsi and \psp decays.Comment: 15 pages, 5 figure

    Measurements of the continuum RudsR_{\rm uds} and RR values in e+ee^+e^- annihilation in the energy region between 3.650 and 3.872 GeV

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    We report measurents of the continuum RudsR_{\rm uds} near the center-of-mass energy of 3.70 GeV, the Ruds(c)+ψ(3770)(s)R_{{\rm uds(c)}+\psi(3770)}(s) and the Rhad(s)R_{\rm had}(s) values in e+ee^+e^- annihilation at 68 energy points in the energy region between 3.650 and 3.872 GeV with the BES-II detector at the BEPC Collodier. We obtain the RudsR_{\rm uds} for the continuum light hadron (containing u, d and s quarks) production near the DDˉD\bar D threshold to be Ruds=2.141±0.025±0.085R_{\rm uds}=2.141 \pm 0.025 \pm 0.085.Comment: 5 pages, 3 figure

    Measurement of the cross section for e^+e^- -> ppbar at center-of-mass energies from 2.0 to 3.07 GeV

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    Cross sections for e^+e^- -> ppbar have been measured at 10 center-of-mass energies from 2.0 to 3.07 GeV by the BESII experiment at the BEPC, and proton electromagnetic form factors in the time-like region have been determined.Comment: 6 pages, 3 figure
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