RESUMO
Low toxic graphene quantum dot (GQD) was synthesized by pyrolyzing citric acid in alkaline solution and characterized by ultraviolet–visible (UV–vis) spectroscopy, X-ray diffraction (XRD), atomic force micro-scopy (AFM), spectrofluorimetery and dynamic light scattering (DLS) techniques. GQD was used for electrode modification and electro-oxidation of doxorubicin (DOX) at low potential. A substantial de-crease in the overvoltage ( ? 0.56 V) of the DOX oxidation reaction (compared to ordinary electrodes) was observed using GQD as coating of glassy carbon electrode (GCE). Differential pulse voltammetry was used to evaluate the analytical performance of DOX in the presence of phosphate buffer solution (pH 4.0) and good limit of detection was obtained by the proposed sensor. Such ability of GQD to promote the DOX electron-transfer reaction suggests great promise for its application as an electrochemical sensor.
RESUMO
BACKGROUND: To investigate protocols of remission induction therapy for prevention of morbidity of acute myeloid leukemia. MATERIALS AND METHODS: The responses of 150 patients to "2+5" and "3+7" protocols during 1996-2003 were assessed and analyzed with the Chi-Square method. RESULTS: Complete remission was observed in 30% of cases treated with 2 days of daunorubicin and 5 days of cytarabine (2+5 regimen). Remission was increased to 52.5% when patients were treated with 3+7 regimens with the same drugs. Partial remission resulted in 25 and 10 percent of cases, respectively. CONCLUSION: As in previous studies the 3+7 regimen was demonstrated to be more effective than the 2+5 regimen in our hospital (p=0.0009).