685 research outputs found

    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

    A Study of Brain Networks Associated with Swallowing Using Graph-Theoretical Approaches

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    Functional connectivity between brain regions during swallowing tasks is still not well understood. Understanding these complex interactions is of great interest from both a scientific and a clinical perspective. In this study, functional magnetic resonance imaging (fMRI) was utilized to study brain functional networks during voluntary saliva swallowing in twenty-two adult healthy subjects (all females, 23.1±1.52 years of age). To construct these functional connections, we computed mean partial correlation matrices over ninety brain regions for each participant. Two regions were determined to be functionally connected if their correlation was above a certain threshold. These correlation matrices were then analyzed using graph-theoretical approaches. In particular, we considered several network measures for the whole brain and for swallowing-related brain regions. The results have shown that significant pairwise functional connections were, mostly, either local and intra-hemispheric or symmetrically inter-hemispheric. Furthermore, we showed that all human brain functional network, although varying in some degree, had typical small-world properties as compared to regular networks and random networks. These properties allow information transfer within the network at a relatively high efficiency. Swallowing-related brain regions also had higher values for some of the network measures in comparison to when these measures were calculated for the whole brain. The current results warrant further investigation of graph-theoretical approaches as a potential tool for understanding the neural basis of dysphagia. © 2013 Luan et al

    Bifunctional non-noble metal oxide nanoparticle electrocatalysts through lithium-induced conversion for overall water splitting

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    Developing earth-abundant, active and stable electrocatalysts which operate in the same electrolyte for water splitting, including oxygen evolution reaction and hydrogen evolution reaction, is important for many renewable energy conversion processes. Here we demonstrate the improvement of catalytic activity when transition metal oxide (iron, cobalt, nickel oxides and their mixed oxides) nanoparticles (~20 nm) are electrochemically transformed into ultra-small diameter (2–5 nm) nanoparticles through lithium-induced conversion reactions. Different from most traditional chemical syntheses, this method maintains excellent electrical interconnection among nanoparticles and results in large surface areas and many catalytically active sites. We demonstrate that lithium-induced ultra-small NiFeOx nanoparticles are active bifunctional catalysts exhibiting high activity and stability for overall water splitting in base. We achieve 10 mA cm−2 water-splitting current at only 1.51 V for over 200 h without degradation in a two-electrode configuration and 1 M KOH, better than the combination of iridium and platinum as benchmark catalysts.open10

    Groundwater Nitrogen Pollution and Assessment of Its Health Risks: A Case Study of a Typical Village in Rural-Urban Continuum, China

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    Protecting groundwater from nitrogen contamination is an important public-health concern and a major national environmental issue in China. In this study, we monitored water quality in 29 wells from 2009 to 2010 in a village in Shanghai city, whick belong to typical rural-urban continuum in China. The total N and NO3-N exhibited seasonal changes, and there were large fluctuations in NH4-N in residential areas, but without significant seasonal patterns. NO2-N in the water was not stable, but was present at high levels. Total N and NO3-N were significantly lower in residential areas than in agricultural areas. The groundwater quality in most wells belonged to Class III and IV in the Chinese water standard, which defines water that is unsuitable for human consumption. Our health risk assessments showed that NO3-N posed the greatest carcinogenic risk, with risk values ranging from 19×10−6 to 80×10−6, which accounted for more than 90% of the total risk in the study area

    Inflammatory cytokines and biofilm production sustain Staphylococcus aureus outgrowth and persistence: A pivotal interplay in the pathogenesis of Atopic Dermatitis

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    Individuals with Atopic dermatitis (AD) are highly susceptible to Staphylococcus aureus colonization. However, the mechanisms driving this process as well as the impact of S. aureus in AD pathogenesis are still incompletely understood. In this study, we analysed the role of biofilm in sustaining S. aureus chronic persistence and its impact on AD severity. Further we explored whether key inflammatory cytokines overexpressed in AD might provide a selective advantage to S. aureus. Results show that the strength of biofilm production by S. aureus correlated with the severity of the skin lesion, being significantly higher (P < 0.01) in patients with a more severe form of the disease as compared to those individuals with mild AD. Additionally, interleukin (IL)-β and interferon γ (IFN-γ), but not interleukin (IL)-6, induced a concentration-dependent increase of S. aureus growth. This effect was not observed with coagulase-negative staphylococci isolated from the skin of AD patients. These findings indicate that inflammatory cytokines such as IL1-β and IFN-γ, can selectively promote S. aureus outgrowth, thus subverting the composition of the healthy skin microbiome. Moreover, biofilm production by S. aureus plays a relevant role in further supporting chronic colonization and disease severity, while providing an increased tolerance to antimicrobials

    In vitro generation of cytotoxic and regulatory T cells by fusions of human dendritic cells and hepatocellular carcinoma cells

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    <p>Abstract</p> <p>Background</p> <p>Human hepatocellular carcinoma (HCC) cells express WT1 and/or carcinoembryonic antigen (CEA) as potential targets for the induction of antitumor immunity. In this study, generation of cytotoxic T lymphocytes (CTL) and regulatory T cells (Treg) by fusions of dendritic cells (DCs) and HCC cells was examined.</p> <p>Methods</p> <p>HCC cells were fused to DCs either from healthy donors or the HCC patient and investigated whether supernatants derived from the HCC cell culture (HCCsp) influenced on the function of DCs/HCC fusion cells (FCs) and generation of CTL and Treg.</p> <p>Results</p> <p>FCs coexpressed the HCC cells-derived WT1 and CEA antigens and DCs-derived MHC class II and costimulatory molecules. In addition, FCs were effective in activating CD4<sup>+ </sup>and CD8<sup>+ </sup>T cells able to produce IFN-γ and inducing cytolysis of autologous tumor or semiallogeneic targets by a MHC class I-restricted mechanism. However, HCCsp induced functional impairment of DCs as demonstrated by the down-regulation of MHC class I and II, CD80, CD86, and CD83 molecules. Moreover, the HCCsp-exposed DCs failed to undergo full maturation upon stimulation with the Toll-like receptor 4 agonist penicillin-inactivated <it>Streptococcus pyogenes</it>. Interestingly, fusions of immature DCs generated in the presence of HCCsp and allogeneic HCC cells promoted the generation of CD4<sup>+ </sup>CD25<sup>high </sup>Foxp3<sup>+ </sup>Treg and inhibited CTL induction in the presence of HCCsp. Importantly, up-regulation of MHC class II, CD80, and CD83 on DCs was observed in the patient with advanced HCC after vaccination with autologous FCs. In addition, the FCs induced WT1- and CEA-specific CTL that were able to produce high levels of IFN-γ.</p> <p>Conclusion</p> <p>The current study is one of the first demonstrating the induction of antigen-specific CTL and the generation of Treg by fusions of DCs and HCC cells. The local tumor-related factors may favor the generation of Treg through the inhibition of DCs maturation; however, fusion cell vaccination results in recovery of the DCs function and induction of antigen-specific CTL responses in vitro. The present study may shed new light about the mechanisms responsible for the generation of CTL and Treg by FCs.</p

    Exocytotic catecholamine release is not associated with cation flux through channels in the vesicle membrane but Na+ influx through the fusion pore

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    Release of charged neurotransmitter molecules through a narrow fusion pore requires charge compensation by other ions. It has been proposed that this may occur by ion flow from the cytosol through channels in the vesicle membrane, which would generate a net outward current. This hypothesis was tested in chromaffin cells using cell-attached patch amperometry that simultaneously measured catecholamine release from single vesicles and ionic current across the patch membrane. No detectable current was associated with catecholamine release indicating that <2% of cations, if any, enter the vesicle through its membrane. Instead,we show that flux of catecholamines through the fusion pore, measured as an amperometric foot signal, decreases when the extracellular cation concentration is reduced. The results reveal that the rate of transmitter release through the fusion pore is coupled to net Na+ influx through the fusion pore, as predicted by electrodiffusion theory applied to fusion-pore permeation,and suggest a prefusion rather than postfusion role for vesicular cation channels

    Branched-chain amino acid aminotransferase 2 regulates ferroptotic cell death in cancer cells

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    Ferroptosis, a form of iron-dependent cell death driven by cellular metabolism and iron-dependent lipid peroxidation, has been implicated as a tumor-suppressor function for cancer therapy. Recent advance revealed that the sensitivity to ferroptosis is tightly linked to numerous biological processes, including metabolism of amino acid and the biosynthesis of glutathione. Here, by using a high-throughput CRISPR/Cas9-based genetic screen in HepG2 hepatocellular carcinoma cells to search for metabolic proteins inhibiting ferroptosis, we identified a branched-chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib, and sulfasalazine) activated AMPK/SREBP1 signaling pathway through iron-dependent ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 as the key enzyme mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc(-) inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. On the contrary, direct inhibition of BCAT2 by RNA interference, or indirect inhibition by blocking system Xc(-) activity, triggers ferroptosis. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies. Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance

    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 ψπ+πJ/ψ(J/ψγppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\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=186113+6(stat)26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<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

    Cardiovascular Events in Patients Received Combined Fibrate/Statin Treatment versus Statin Monotherapy: Acute Coronary Syndrome Israeli Surveys Data

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    The effect of combination of fibrate with statin on major adverse cardiovascular events (MACE) following acute coronary syndrome (ACS) hospitalization is unclear. The main aim of this study was to investigate the 30-day rate of MACE in patients who participated in the nationwide ACS Israeli Surveys (ACSIS) and were treated on discharge with a fibrate (mainly bezafibrate) and statin combination vs. statin alone.The study population comprised 8,982 patients from the ACSIS 2000, 2002, 2004, 2006, 2008 and 2010 enrollment waves who were alive on discharge and received statin. Of these, 8,545 (95%) received statin alone and 437 (5%) received fibrate/statin combination. MACE was defined as a composite measure of death, recurrent MI, recurrent ischemia, stent thrombosis, ischemic stroke and urgent revascularization.Patients from the combination group were younger (58.1±11.9 vs. 62.9±12.6 years). However, they had significantly more co-morbidities (hypertension, diabetes), current smokers and unfavorable cardio-metabolic profiles (with respect to glucose, total cholesterol, triglyceride and HDL-cholesterol). Development of MACE was recorded in 513 (6.0%) patients from the statin monotherapy group vs. 13 (3.2%) from the combination group, p = 0.01. 30-day re-hospitalization rate was significantly lower in the combination group: 68 (15.6%) vs. 1691 (19.8%) of patients, respectively; p = 0.03. Multivariable analysis identified the fibrate/statin combination as an independent predictor of reduced risk of MACE with odds ratio of 0.54, 95% confidence interval 0.32–0.94.A significantly lower risk of 30-day MACE rate was observed in patients receiving combined fibrate/statin treatment following ACS compared with statin monotherapy. However, caution should be exercised in interpreting these findings taking into consideration baseline differences between our observational study groups
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