35 research outputs found

    Efficient generation of highly crystalline carbon quantum dots via electrooxidation of ethanol for rapid photodegradation of organic dyes

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    Achieving versatile routes to generate crystalline carbon-based nanostructures has become a fervent pursuit in photocatalysis-related fields. We demonstrate that the direct electrooxidation of ethanol, performed on Ni foam, yields ultra-small and highly crystalline graphene-like structures named carbon quantum dots (CQDs). We perform simulations of various sp2 and sp3 domains in order to understand the optical properties of CQDs by accounting their contribution as absorbance/luminescent centers in the overall optical response. Experiments and simulations reveal that absorbance bands for as-synthesized CQDs are dominated by small sp2 domains comprised of r7 aromatic-rings. After 48 h synthesis, the dispersion transition from yellow to red, exhibiting new and red shifted absorbance bands. Furthermore, fluorescence emission is governed by medium-sized sp 2 domains (with aromatic ring counts r12) and oxygen-containing groups. These oxygen-rich groups within the CQDs, confirmed by FT-IR and XPS, are responsible for the fast photodegradation of organic dyes, with B90% of methylene blue (MB) being degraded within the first 5 min of light exposure. Our work provides crucial insights about the electrochemical synthesis and overall optical properties of carbon nanostructures, while being effective and reliable toward the degradation of contaminants in water

    Quetiapine in the treatment of schizophrenia and related disorders

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    Quetiapine was developed in 1985 by scientists at AstraZeneca (formerly Zeneca) Pharmaceuticals. It received official US Food and Drug Administration approval in September 1997 and approval in Germany in 2000. Since then, quetiapine has been used in the treatment of severe mental illness in approximately 70 countries including Canada, most Western European countries, and Japan. Quetiapine is a dibenzothiazepine derivative with a relatively broad receptor binding profile. It has major affinity to cerebral serotonergic (5HT2A), histaminergic (H1), and dopaminergic D1 and D2 receptors, moderate affinity to α1- und α2-adrenergic receptors, and minor affinity to muscarinergic M1 receptors; it demonstrates a substantial selectivity for the limbic system. This receptor occupancy profile with relatively higher affinity for the 5HT2A receptor compared with the D2 receptor is in part responsible for the antipsychotic characteristics and low incidence of extrapyramidal side-effects of quetiapine. The efficacy of quetiapine in reducing positive and negative symptoms of schizophrenia has been proven in several clinical trials with placebo-controlled comparators. Quetiapine has also demonstrated robust efficacy for treatment of cognitive, anxious-depressive, and aggressive symptoms in schizophrenia. Long-term trials show sustained tolerability for a broad spectrum of symptoms. Quetiapine has also proven efficacy and tolerability in the treatment of moderate to severe manic episodes, and in the treatment of juveniles with oppositional-defiant or conduct disorders, and in the geriatric dementia population. Recent data indicate that quetiapine may also be effective in the treatment of bipolar depressive symptoms without increasing the risk of triggering manic episodes, and in borderline personality disorder. In comparison with other antipsychotics, quetiapine has a favorable side-effect profile. In clinical trials only small insignificant prolongations of the QT interval were observed. Weight-gain liabilities and new-onset metabolic side-effects occupy a middle-ground among newer antipsychotics. As a result of its good efficacy and tolerability profile quetiapine has become well established in the treatment of schizophrenia and manic episodes

    Paclitaxel, vinorelbine and 5-fluorouracil in breast cancer patients pretreated with adjuvant anthracyclines

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    We investigated the activity and toxicity of a combination of vinorelbine (VNB), paclitaxel (PTX) and 5-fluorouracil (5-FU) continuous infusion administered as first-line chemotherapy in metastatic breast cancer patients pretreated with adjuvant anthracyclines. A total of 61 patients received a regimen consisting of VNB 25 mg m−2 on days 1 and 15, PTX 60 mg m−2 on days 1, 8 and 15 and continuous infusion of 5-FU at 200 mg m−2 every day. Cycles were repeated every 28 days. Disease response was evaluated by both RECIST and World Health Organization (WHO) criteria. Objective responses were recorded in 39 of 61 patients (64.0%) assessed by WHO and in 36 of 50 patients (72.0%) assessable by RECIST criteria. Complete remission occurred in 15 (24.6%) and 14 patients (28.0%), respectively. The median time to progression and overall survival of entire population was 10.6 and 27.3 months, respectively, and median duration of complete response was 14.8 months. The dose-limiting toxicity was myelosuppression (leucopenia grade 3/4 in 52.5% of patients). Grade 3/4 nonhaematologic toxicities included mucositis/diarrhoea in 13.1%, skin in 3.3% and cardiac in 1.6% of patients. Grade 2/3 neurotoxicity was observed in five patients (7.2%). The VNB, PTX and 5-FU continuous infusion combination regimen was active and manageable. Complete responses were frequent and durable

    The Charge Asymmetry in W-Boson Decays Produced in p-pbar Collisions at sqrt(s) = 1.8 TeV

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    The charge asymmetry has been measured using 19,039 W19,039~W decays recorded by the CDF detector during the 1992-93 run of the Tevatron Collider. The asymmetry is sensitive to the ratio of dd and uu quark distributions to x<0.01x<0.01 at Q2MW2Q^2 \approx M_W^2, where nonperturbative effects are minimal. It is found that of the two current sets of parton distributions, those of Martin, Roberts and Stirling (MRS) are favored over the sets most recently produced by the CTEQ collaboration. The WW asymmetry data provide a stronger constraints on d/ud/u ratio than the recent measurements of F2μn/F2μpF_2^{\mu n}/F_2^{\mu p} which are limited by uncertainties originating from deutron corrections.Comment: to be published in PR

    Measurement of correlated μoverlineb\mu - {overline b} jet cross sections in ppˉp {\bar p} collisions at s=1.8\sqrt{s}=1.8 TeV

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    We report on measurements of differential μbˉ\mu - {\bar b} cross sections, where the muon is from a semi-leptonic bb decay and the bˉ{\bar b} is identified using precision track reconstruction in jets. The semi-differential correlated cross sections, dσ\sigma/d\Et^{{\bar b}}, dσ\sigma/d\pt^{{\bar b}}, and dσ\sigma/dδϕ(μbˉ)\delta\phi(\mu - {\bar b}) for \pt^{\mu}>~9 GeV/c, ημ|\eta^{\mu}|~10 GeV, ηbˉ<|\eta^{{\bar b}}|<~1.5, are presented and compared to next-to-leading order QCD calculations.Comment: Uses Latex, Article 12 point, figures appended as uuencoded file The full PostScript available via WWW at http://www-cdf.fnal.gov/physics/pub95/cdf3164_mu_bbar_prd_final.p

    Measurement of the BB Meson Differential Cross Section, dσ/dpTd\sigma/dp_T, in ppˉp\bar{p} Collisions at s=1.8\sqrt{s} = 1.8 TeV

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    This paper presents the first direct measurement of the BB meson differential cross section, dσ/dpTd\sigma/dp_T, in ppˉp\bar{p} collisions at s=1.8\sqrt{s}=1.8 TeV using a sample of 19.3±0.719.3 \pm 0.7 pb1^{-1} accumulated by the Collider Detector at Fermilab (CDF). The cross section is measured in the central rapidity region y6.0|y| 6.0 GeV/cc by fully reconstructing the BB meson decays B+J/ψK+B^{+}\to J/\psi K^{+} and B0J/ψK0(892)B^{0}\to J/\psi K^{*0}(892), where J/ψμ+μJ/\psi \to \mu^+\mu^- and K0K+πK^{*0} \to K^+ \pi^-. A comparison is made to the theoretical QCD prediction calculated at next-to-leading order.Comment: 14 pages. Submitted to Phys. Rev. Lett. The postscript file is at http://www-cdf.fnal.gov/physics/pub95/cdf2893_bexcl_xsection.p

    Limits on WWZWWZ and WWγWW\gamma couplings from WWWW and WZWZ production in ppp\overline{p} collisions at s=1.8\sqrt{s} = 1.8 TeV

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    Direct limits are set on WWZWWZ and WWγWW\gamma three-boson couplings in a search for WWWW and WZWZ production with high transverse momentum in ppp\overline{p} collisions at s=1.8\sqrt{s} = 1.8 TeV, using the Collider Detector at Fermilab. The results are in agreement with the SU(2) ×\times U(1) model of electroweak interactions. Assuming Standard Model WWγWW\gamma coupling, the the limits are interpreted as direct evidence for a non-zero WWZWWZ coupling at subprocess energies near 500 GeV. Alternatively, assumiong identical WWZWWZ and WWγWW\gamma couplings, bounds 0.11<κ<2.27-0.11 < \kappa < 2.27 and 0.81<λ<0.84-0.81 < \lambda < 0.84 are obtained at 95%95\% CL for a form factor scale 1000 GeV.Comment: 16 pages, submitted to PRL, URL: http://www-cdf.fnal.gov/physics/pub95/cdf2951_vvprl.p
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