11 research outputs found

    Molecularly Imprinted Solid Phase Extraction Aiding the Analysis of Disease Biomarkers

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    Low concentrations of biomarkers as well as the complexity of biological samples make the clinical diagnoses of several diseases a challenging task. Sample preparation protocols remain a fundamental piece in the puzzle of analytical processes, and smart sorbents including molecularly imprinted polymers (MIPs) have been successfully used in this case. In this review, we depict the state of art for the rational design of MIPs to be used in solid phase extraction of disease biomarkers from biological samples. The topics are divided into (1) strategies for MIP syntheses, (2) setups for sample preparation protocols with MIPs, (3) the applications of these combined principles in the analyses of different classes of disease biomarkers, and (4) remaining challenges and future trends for the application of Molecular Imprinting Technology in sample preparation for clinical diagnosis.The authors are thankful to the Fundação à Pesquisa do Estado de Minas Gerais (FAPEMIG, Belo Horizonte, Brazil); the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brasilia, Brazil) and the Coordination for the Improvement of Higher Education Personnel (CAPES, Brasilia, Brazil) for financial support (process 88881.133746/2016-01) and the scholarship funding for Matheus Siqueira Silva/PDSE/ Processo no. {88881.133746/2016-01}.info:eu-repo/semantics/publishedVersio

    Urinary neopterin quantification by reverse-phase high-performance liquid chromatography with ultraviolet detection

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    Neopterin plays an important role in the malignant disease diagnostics. However, the methods employed in neopterin determination are generally difficult and/or time consuming. The aim of this work was to standardize a practical method to quantify neopterin using high-performance liquid chromatography-ultraviolet (HPLC-UV) and quantify it in patients with systemic lupus erythematosus (SLE). Urine was collected from healthy subjects (n=49), patients with inactive (n=15), active (n=28), and highly active SLE (n=6). The HPLC was performed using two coupled reverse-phase columns eluted with 150 mM sodium phosphate, pH 4.0, under a flow rate of 0.8 ml/min, with UV detector set at 353 nm and 100-fold diluted urines. The inter- and intra-assay studies presented an imprecision of 12.5% and 12.9% for quality controls of 3.94 and 1.1 mol/ml, respectively. Recovery from 79.5% to 82% was observed throughout the assay's linear range. Subjects with active (874.2±165.38 mol/mol creatinin) and highly active SLE (1753.8±453.9 mol/mol creatinin) showed three- and sixfold increased neopterin levels, respectively, compared to subjects with inactive SLE (314.3±121.3 mol/mol creatinin) and healthy subjects (294.6±178.6 mol/mol creatinin) (

    Tunneling current modulation in atomically precise graphene nanoribbon heterojunctions

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    Lateral heterojunctions of atomically precise graphene nanoribbons GNRs hold promise for applications in nanotechnology, yet their charge transport and most of the spectroscopic properties have not been investigated. Here, we synthesize a monolayer of multiple aligned heterojunctions consisting of quasi metallic and wide bandgap GNRs, and report characterization by scanning tunneling microscopy, angle resolved photoemission, Raman spectroscopy, and charge transport. Comprehensive transport measurements as a function of bias and gate voltages, channel length, and temperature reveal that charge transport is dictated by tunneling through the potential barriers formed by wide bandgap GNR segments. The current voltage characteristics are in agreement with calculations of tunneling conductance through asymmetric barriers. We fabricate a GNR heterojunctions based sensor and demonstrate greatly improved sensitivity to adsorbates compared to graphene based sensors. This is achieved via modulation of the GNR heterojunction tunneling barriers by adsorbate

    Energy scan of the e+ehb(nP)π+πe^+e^- \to h_b(nP)\pi^+\pi^- (n=1,2)(n=1,2) cross sections and evidence for the Υ(11020)\Upsilon(11020) decays into charged bottomonium-like states

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    Using data collected with the Belle detector in the energy region of the Υ(10860)\Upsilon(10860) and Υ(11020)\Upsilon(11020) resonances we measure the e+ehb(nP)π+πe^+e^- \to h_b(nP)\pi^+\pi^- (n=1,2)(n=1,2) cross sections. Their energy dependences show clear Υ(10860)\Upsilon(10860) and Υ(11020)\Upsilon(11020) peaks with a small or no non-resonant contribution. We study resonant structure of the Υ(11020)hb(nP)π+π\Upsilon(11020) \to h_b(nP)\pi^+\pi^- transitions and find evidence that they proceed entirely via intermediate charged bottomonium-like states Zb(10610)Z_b(10610) and/or Zb(10650)Z_b(10650) (with current statistics we can not discriminate hypotheses of one or two intermediate states).Using data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider, we measure the energy dependence of the e+e-→hb(nP)π+π- (n=1, 2) cross sections from thresholds up to 11.02 GeV. We find clear ϒ(10860) and ϒ(11020) peaks with little or no continuum contribution. We study the resonant substructure of the ϒ(11020)→hb(nP)π+π- transitions and find evidence that they proceed entirely via the intermediate isovector states Zb(10610) and Zb(10650). The relative fraction of these states is loosely constrained by the current data: The hypothesis that only Zb(10610) is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only Zb(10650) is produced is not excluded at a significant level.Using data collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider, we measure the energy dependence of the e+ehb(nP)π+πe^+e^- \to h_b(nP)\pi^+\pi^- (n=1,2)(n=1,2) cross sections from thresholds up to 11.0211.02\,GeV. We find clear Υ(10860)\Upsilon(10860) and Υ(11020)\Upsilon(11020) peaks with little or no continuum contribution. We study the resonant substructure of the Υ(11020)hb(nP)π+π\Upsilon(11020) \to h_b(nP)\pi^+\pi^- transitions and find evidence that they proceed entirely via the intermediate isovector states Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650). The relative fraction of these states is loosely constrained by the current data: the hypothesis that only Zb(10610)Z_b(10610) is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only Zb(10650)Z_b(10650) is produced is not excluded at a significant level

    Measurements of branching fraction and CPCP asymmetry of the Bˉ0(B0)KS0Kπ±\bar{B}^{0}(B^{0})\to K^{0}_{S}K^{\mp}\pi^{\pm} decay at Belle

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    International audienceWe report the measurement of the branching fraction and CPCP asymmetry for the Bˉ0(B0)KS0Kπ±\bar{B}^{0}(B^{0})\to K^{0}_{S}K^{\mp}\pi^{\pm} decay. The analysis is performed on a data sample of 711 fb1\rm{fb}^{-1} collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^{+}e^{-} collider. We obtain a branching fraction of (3.60±0.33±0.15)×106(3.60\pm0.33\pm0.15)\times10^{-6} and an ACP\mathcal{A}_{CP} of (8.5±8.9±0.2)%(-8.5\pm8.9\pm0.2)\%, where the first uncertainties are statistical and the second are systematic. Hints of peaking structures are also observed in the differential branching fraction as functions of Dalitz variables

    Test of lepton flavor universality and search for lepton flavor violation in BKB \rightarrow K\ell \ell decays

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    International audienceWe present measurements of the branching fractions for the decays B → Kμ+^{+}μ^{−} and B → Ke+^{+}e^{−}, and their ratio (RK_{K}), using a data sample of 711 fb1^{−1} that contains 772 × 106BB^{6} B\overline{B} events. The data were collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+^{+}e^{−} collider. The ratio RK_{K} is measured in five bins of dilepton invariant-mass-squared (q2^{2}): q2^{2} ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2^{2}/c4^{4}, along with the whole q2^{2} region. The RK_{K} value for q2^{2} ∈ (1.0, 6.0) GeV2^{2}/c4^{4} is 1.030.24+0.28 {1.03}_{-0.24}^{+0.28} ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK_{K} are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q2^{2} bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2^{2} ∈ (1.0, 6.0) GeV2^{2}/c4^{4} bin in the mode with muon final states. The measured differential branching fractions, dB d\mathrm{\mathcal{B}} /dq2^{2}, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ±^{±}e^{∓} decays and set 90% confidence-level upper limits on the branching fraction in the range of 108^{−8} for B+^{+} → K+^{+}μ±^{±}e^{∓}, and B0^{0} → K0^{0}μ±^{±}e^{∓} modes.[graphic not available: see fulltext

    Test of lepton flavor universality in BK+{B\to K^\ast\ell^+\ell^-} decays at Belle

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    We present a measurement of RKR_{K^{\ast}}, the ratio of the branching fractions B(BKμ+μ){\cal B}(B\to K^\ast \mu^+ \mu^-) and B(BKe+e){\cal B}(B\to K^\ast e^+ e^-), for both charged and neutral BB mesons. The ratio for charged BB mesons, RK+R_{K{^{\ast +}}}, is the first measurement ever performed. The analysis is based on a data sample of 711 fb1711~\mathrm{fb}^{-1}, containing 772×106772\times 10^{6} BBˉB\bar B events, recorded at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider

    Measurement of the DD^{\ast-} polarization in the decay B0Dτ+ντB^0 \to D^{\ast -}\tau^+\nu_{\tau}

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    International audienceWe report the first measurement of the DD^{\ast -} meson polarization in the decay B0Dτ+ντB^0 \to D^{*-} \tau^+\nu_{\tau} using the full data sample of 772×106\times 10^6 BBˉB\bar{B} pairs recorded with the Belle detector at the KEKB electron-positron collider. Our result, FLD=0.60±0.08(stat)±0.04(sys)F_L^{D^\ast} = 0.60 \pm 0.08 ({\rm stat}) \pm 0.04 ({\rm sys}), where FLDF_L^{D^\ast} denotes the DD^{\ast-} meson longitudinal polarization fraction, agrees within about 1.71.7 standard deviations of the standard model prediction

    Measurement of R(D)\mathcal{R}(D) and R(D)\mathcal{R}(D^{\ast}) with a semileptonic tagging method

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    We report a measurement of the ratios of branching fractions R(D)=B(BˉDτνˉτ)/B(BˉDνˉ)\mathcal{R}(D) = {\cal B}(\bar{B} \to D \tau^- \bar{\nu}_{\tau})/{\cal B}(\bar{B} \to D \ell^- \bar{\nu}_{\ell}) and R(D)=B(BˉDτνˉτ)/B(BˉDνˉ)\mathcal{R}(D^{\ast}) = {\cal B}(\bar{B} \to D^* \tau^- \bar{\nu}_{\tau})/{\cal B}(\bar{B} \to D^* \ell^- \bar{\nu}_{\ell}), where \ell denotes an electron or a muon. The results are based on a data sample containing 772×106772\times10^6 BBˉB\bar{B} events recorded at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB e+ee^+ e^- collider. The analysis utilizes a method where the tag-side BB meson is reconstructed in a semileptonic decay mode, and the signal-side τ\tau is reconstructed in a purely leptonic decay. The measured values are R(D)=0.307±0.037±0.016\mathcal{R}(D)= 0.307 \pm 0.037 \pm 0.016 and R(D)=0.283±0.018±0.014\mathcal{R}(D^{\ast})= 0.283 \pm 0.018 \pm 0.014, where the first uncertainties are statistical and the second are systematic. These results are in agreement with the Standard Model predictions within 0.20.2 and 1.11.1 standard deviations, respectively, while their combination agrees with the Standard Model predictions within 1.21.2 standard deviations

    Study of χbJ(nP)ωΥ(1S)\chi_{bJ}(nP) \rightarrow \omega \Upsilon(1S) at Belle

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    We report results from a study of hadronic transitions of the χbJ(nP)\chi_{bJ}(nP) states of bottomonium at Belle. The PP-wave states are reconstructed in transitions to the Υ(1S)\Upsilon(1S) with the emission of an ω\omega meson. The transitions of the n=2n=2 triplet states provide a unique laboratory in which to study nonrelativistic quantum chromodynamics, as the kinematic threshold for production of an ω\omega and Υ(1S)\Upsilon(1S) lies between the J=0J=0 and J=1J=1 states. A search for the χbJ(3P)\chi_{bJ}(3P) states is also reported
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