1,417 research outputs found

    Graphite Electrode Modified with a New Phenothiazine Derivative and with Carbon Nanotubes for NADH Electrocatalytic Oxidation

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    The electrochemical behavior of a modified electrode obtained by immobilization of single-walled carbon nanotubes onto a graphite electrode modified with a new phenothiazine derivative, bis-phenothiazin-3-yl methane (BPhM), G/BPhM-CNT, has been evaluated and compared with BPhM adsorbed on graphite electrode (G/BPhM). The G/BPhM-CNT electrode presents improved performances for NADH electrocatalytic oxidation in comparison with G/BPhM electrode, expressed by: (i) a significant increase of electrocatalytic rate constant (kobs,[NADH] 0) for NADH oxidation (856.32 L mol–1 s–1 for G/BPhM-CNT and 51.63 L mol–1 s–1 for G/BPhM, in phosphate buffer, pH 7); (ii) the obtained amperometric sensors for NADH detection present increase sensitivity (S = 6.9 mA L mol–1 for G/BPhM-CNT and S = 0.55 mA L mol–1 for G/BPhM, pH 7)

    Corrosion Behavior of Composite Coatings Obtained by Electrolytic Codeposition of Copper with Al2O3 Nanoparticles

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    Composite coatings of copper incorporating Al2O3 nanoparticles electrodeposited on carbon steel were obtained and characterized. By using electrochemical methods such as open circuit potential (ocp) measurements, polarization curves and electrochemical impedance spectroscopy, the corrosion behavior of the Al2O3-copper nanocomposite coatings was examined. The corrosion parameters determined from the polarization curves recorded in Na2SO4 solution (pH 3) indicate that the corrosion process on copper-Al2O3 composite surface is slower than on pure copper. The impedance spectra recorded at the ocp showed in all cases an increase of the polarization resistance in time, which may be explained by the development of corrosion products on the electrode surface. Using a (2RC) equivalent electrical circuit, the process parameters were estimated by non-linear regression calculations with a Simplex method. The Al2O3 particles embedded in the electroplated copper, increase the polarization resistance and decrease the corrosion rates as compared with electrodeposited pure copper. The electrochemical results were corroborated with those obtained by SEM and EDX investigations

    Cost-Effectiveness of Bosutinib for the Treatment of Adult Patients with Chronic Phase Chronic Myeloid Leukemia in the Second-Line Setting

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    Background A recently conducted matching-adjusted indirect comparison demonstrated that bosutinib improved progression-free survival, and delayed progression to advanced disease compared with dasatinib and nilotinib in patients with second line (2L) chronic-phase chronic myeloid leukemia (CP-CML). However, the long-term clinical and economic impact of using bosutinib versus dasatinib and nilotinib has not been evaluated. The objective was to determine the cost-effectiveness of bosutinib compared with dasatinib and bosutinib compared with nilotinib from a US payer perspective. Methods A cost-effectiveness model was developed using partition survival methods and three health states: progression-free, progression, and death. Trial data (individual patient-level and aggregate-level data) informed the progression-free and overall survival estimates. Costs included drugs and medical resource use. Utility values were obtained from literature. Sensitivity analyses (SAs) included one-way and probabilistic sensitivity analyses (PSAs). Results Comparing bosutinib versus dasatinib resulted in a gain of 0.4 discounted life years, 1.5 quality-adjusted life years (QALYs), and incremental costs of 28,459(valuesin2020USdollars),foranincrementalcost−effectivenessratio(ICER)of28,459 (values in 2020 US dollars), for an incremental cost-effectiveness ratio (ICER) of 19,811/QALY gained. Comparing bosutinib versus nilotinib resulted in a gain of 0.8 discounted life-years, 1.8 QALYs, and incremental costs of 76,563,foranICERof76,563, for an ICER of 41,932/QALY gained. Drug costs and extrapolation distribution type were the main drivers of the model in the one-way SAs. In the PSAs, bosutinib had >90% and >80% probabilities of being cost-effective at a willingness-to-pay threshold of $100,000/QALY versus dasatinib and nilotinib, respectively. Conclusions Our results suggest that compared with dasatinib and nilotinib, bosutinib may represent good value for money for treating 2L CP-CML patients
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