11 research outputs found
Molecularly Imprinted Solid Phase Extraction Aiding the Analysis of Disease Biomarkers
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
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
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 cross sections and evidence for the decays into charged bottomonium-like states
Using data collected with the Belle detector in the energy region of the and resonances we measure the cross sections. Their energy dependences show clear and peaks with a small or no non-resonant contribution. We study resonant structure of the transitions and find evidence that they proceed entirely via intermediate charged bottomonium-like states and/or (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 collider, we measure the energy dependence of the cross sections from thresholds up to GeV. We find clear and peaks with little or no continuum contribution. We study the resonant substructure of the transitions and find evidence that they proceed entirely via the intermediate isovector states and . The relative fraction of these states is loosely constrained by the current data: the hypothesis that only is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only is produced is not excluded at a significant level
Measurements of branching fraction and asymmetry of the decay at Belle
International audienceWe report the measurement of the branching fraction and asymmetry for the decay. The analysis is performed on a data sample of 711 collected at the resonance with the Belle detector at the KEKB asymmetric-energy collider. We obtain a branching fraction of and an of , 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 decays
International audienceWe present measurements of the branching fractions for the decays B → Kμμ and B → Kee, and their ratio (R), using a data sample of 711 fb that contains 772 × 10 events. The data were collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy ee collider. The ratio R is measured in five bins of dilepton invariant-mass-squared (q): q ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV/c, along with the whole q region. The R value for q ∈ (1.0, 6.0) GeV/c is ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for R are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q ∈ (1.0, 6.0) GeV/c bin in the mode with muon final states. The measured differential branching fractions, /dq, 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 → Kμe decays and set 90% confidence-level upper limits on the branching fraction in the range of 10 for B → Kμe, and B → Kμe modes.[graphic not available: see fulltext
Test of lepton flavor universality in decays at Belle
We present a measurement of , the ratio of the branching fractions and , for both charged and neutral mesons. The ratio for charged mesons, , is the first measurement ever performed. The analysis is based on a data sample of , containing events, recorded at the resonance with the Belle detector at the KEKB asymmetric-energy collider
Measurement of the polarization in the decay
International audienceWe report the first measurement of the meson polarization in the decay using the full data sample of 772 pairs recorded with the Belle detector at the KEKB electron-positron collider. Our result, , where denotes the meson longitudinal polarization fraction, agrees within about standard deviations of the standard model prediction
Measurement of and with a semileptonic tagging method
We report a measurement of the ratios of branching fractions and , where denotes an electron or a muon. The results are based on a data sample containing events recorded at the resonance with the Belle detector at the KEKB collider. The analysis utilizes a method where the tag-side meson is reconstructed in a semileptonic decay mode, and the signal-side is reconstructed in a purely leptonic decay. The measured values are and , where the first uncertainties are statistical and the second are systematic. These results are in agreement with the Standard Model predictions within and standard deviations, respectively, while their combination agrees with the Standard Model predictions within standard deviations
Study of at Belle
We report results from a study of hadronic transitions of the states of bottomonium at Belle. The -wave states are reconstructed in transitions to the with the emission of an meson. The transitions of the triplet states provide a unique laboratory in which to study nonrelativistic quantum chromodynamics, as the kinematic threshold for production of an and lies between the and states. A search for the states is also reported