908 research outputs found

    Mild autonomic dysfunction in primary SjΓΆgren's syndrome: a controlled study

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    Introduction The aim of this study was to compare cardiovascular autonomic nervous system function in patients with primary SjΓΆgren's syndrome (pSS) with that in control individuals, and to correlate the findings with autonomic symptoms and the presence of exocrine secretory dysfunction. Methods Twenty-seven female patients with pSS and 25 control individuals completed the COMPASS (Composite Autonomic Symptom Scale) self-reported autonomic symptom questionnaire. Beat-to-beat heart rate and blood pressure data in response to five standard cardiovascular reflex tests were digitally recorded using a noninvasive finger pressure cuff and heart rate variability was analyzed by Fourier spectral analysis. Analysis was performed by analysis of variance (ANOVA), multivariate ANOVA and repeated measures ANOVA, as indicated. Factor analysis was utilized to detect relationships between positive autonomic symptoms in pSS patients. Results Multiple, mild autonomic disturbances were observed in pSS patients relating to decreased heart rate variability, decreased blood pressure variability and increased heart rate, which were most evident in response to postural change. There was a strong trend toward an association between decreased heart rate variability and increased severity of the secretomotor, orthostatic, bladder, gastroparesis and constipation self-reported autonomic symptom cluster identified in pSS patients. This symptom cluster was also associated with fatigue and reduced unstimulated salivary flow, and therefore may be an important component of the clinical spectrum of this disease. Conclusion There was evidence of mild autonomic dysfunction in pSS as measured with both cardiovascular reflex testing and self-reported symptoms. Pathogenic autoantibodies targeting M3 muscarinic receptors remain a strong candidate for the underlying pathophysiology, but practical assays for the detection of this autoantibody remain elusive.Fin ZJ Cai, Sue Lester, Tim Lu, Helen Keen, Karyn Boundy, Susanna M Proudman, Anne Tonkin and Maureen Rischmuelle

    Resonances in J/Οˆβ†’Ο•Ο€+Ο€βˆ’J/\psi \to \phi \pi ^+\pi ^- and Ο•K+Kβˆ’\phi K^+K^-

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    A partial wave analysis is presented of J/Οˆβ†’Ο•Ο€+Ο€βˆ’J/\psi \to \phi \pi ^+\pi ^- and Ο•K+Kβˆ’\phi K^+K^- from a sample of 58M J/ψJ/\psi events in the BES II detector. The f0(980)f_0(980) is observed clearly in both sets of data, and parameters of the Flatt\' e formula are determined accurately: M=965Β±8M = 965 \pm 8 (stat) Β±6\pm 6 (syst) MeV/c2^2, g1=165Β±10Β±15g_1 = 165 \pm 10 \pm 15 MeV/c2^2, g2/g1=4.21Β±0.25Β±0.21g_2/g_1 = 4.21 \pm 0.25 \pm 0.21. The ϕππ\phi \pi \pi data also exhibit a strong ππ\pi \pi peak centred at M=1335M = 1335 MeV/c2^2. It may be fitted with f2(1270)f_2(1270) and a dominant 0+0^+ signal made from f0(1370)f_0(1370) interfering with a smaller f0(1500)f_0(1500) component. There is evidence that the f0(1370)f_0(1370) signal is resonant, from interference with f2(1270)f_2(1270). There is also a state in ππ\pi \pi with M=1790βˆ’30+40M = 1790 ^{+40}_{-30} MeV/c2^2 and Ξ“=270βˆ’30+60\Gamma = 270 ^{+60}_{-30} MeV/c2^2; spin 0 is preferred over spin 2. This state, f0(1790)f_0(1790), is distinct from f0(1710)f_0(1710). The Ο•KKΛ‰\phi K\bar K data contain a strong peak due to f2β€²(1525)f_2'(1525). A shoulder on its upper side may be fitted by interference between f0(1500)f_0(1500) and f0(1710)f_0(1710).Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.

    Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0

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    Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous measurements.Comment: 9 pages, 8 figures, RevTex

    First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)

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    The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the first time using a sample of 5.8X10^7 J/\psi events collected by the BESII detector. The product branching fractions are determined to be B(J/\psi-->gamma eta_c)*B(eta_c-->K^+K^-pi^+pi^-pi^+pi^-)=(1.21+-0.32+- 0.23)X10^{-4},B(J/Οˆβˆ’βˆ’>gammaetac)βˆ—B(etacβˆ’βˆ’>Kβˆ—0KΛ‰βˆ—0pi+piβˆ’)=(1.29+βˆ’0.43+βˆ’0.32)X10βˆ’4,B(J/\psi-->gamma eta_c)*B(eta_c-->K^{*0}\bar{K}^{*0}pi^+pi^-)= (1.29+-0.43+-0.32)X10^{-4}, and (J/\psi-->gamma eta_c)* B(eta_c-->pi^+pi^-pi^+pi^-pi^+pi^-)= (2.59+-0.32+-0.48)X10^{-4}. The upper limit for eta_c-->phi pi^+pi^-pi^+pi^- is also obtained as B(J/\psi-->gamma eta_c)*B(eta_c--> phi pi^+pi^-pi^+pi^-)< 6.03 X10^{-5} at the 90% confidence level.Comment: 11 pages, 4 figure

    First observation of psi(2S)-->K_S K_L

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    The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let

    Study of psi(2S) decays to X J/psi

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    Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) -> pi^+ pi^- J/psi are measured. The results are B(psi(2S) -> eta J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.098 \pm 0.005 \pm 0.010, B(psi(2S) -> pi^0 pi^0 J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.570 \pm 0.009 \pm 0.026, and B(psi(2S) -> anything J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 1.867 \pm 0.026 \pm 0.055.Comment: 13 pages, 8 figure

    Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.

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    BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721

    Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials

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    Recent years witnessed a rapid growth of interest of scientific and engineering communities to thermal properties of materials. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range - of over five orders of magnitude - from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. I review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. A special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe prospects of applications of graphene and carbon materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel Οˆβ€²β†’Ο€+Ο€βˆ’J/ψ(J/Οˆβ†’Ξ³ppΛ‰)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06Γ—1081.06\times 10^8 Οˆβ€²\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppΛ‰p\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=1861βˆ’13+6(stat)βˆ’26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Ξ“<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
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