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Contamination of natural water by mercury (Hg 2 + ) and bismuth (Bi 3 + ) metal ions have been extensively studied due to their toxic effects. A validated square-wave anodic stripping voltammetry (SW-ASV) method for determining Bi 3 + and Hg 2 + ions individually and simultaneously is described. A new electrochemical sensor was constructed using a gold (Au) electrode that has been modified with poly(1,2-diaminoanthraquinone) (p-1,2-DAAQ). Scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy were used to characterize the p-1,2-DAAQ/Au modified electrode. Factors such as the polymer film thickness, electrolyte, square wave parameters and preconcentration conditions were optimized to improve the performance of the modified Au electrode. Good linear responses were achieved in the concentration ranges of 1-200 μg L À 1 and 1-50 μg L À 1 forBi 3 + and Hg 2 + , respectively, and the limits of detection were 0.27 μg L À 1 (Bi 3 + ) and 0.29 μg L À 1 (Hg 2 + ). The interference study results illustrated the high selectivity of the modified electrode for detection of Bi 3 + and Hg 2 + . The proposed SW-ASV method was successfully applied for Bi 3 + and Hg 2 + analyses in different real water samples.

Objectives To assess the role of multiparametric magnetic resonance imaging (mp-MRI) in the diagnosis and staging of urinary bladder cancer (BC). Materials and methods Fifty patients diagnosed with bladder masses underwent mp-MRI study. The results of 3 image sets were analyzed and compared with the histopathological results as a reference standard: T2-weighted image (T2WI) plus dynamic contrast-enhanced (DCE), T2WI plus diffusion-weighted images (DWI), and mp-MRI, including T2WI plus DWI and DCE. The diagnostic accuracy of mp-MRI was evaluated using receiver operating characteristic curve analysis. Results The accuracy of T2WI plus DCE for detecting muscle invasion of BC was 79.5% with a fair agreement with histopathological examination ( κ = 0.59); this percentage increased up to 88.6% using T2WI plus DWI, with good agreement with histopathological examination ( κ = 0.74), whereas mp-MRI had the highest overall accuracy (95.4%) and excellent agreement with histopathological data ( κ = 0.83). Multiparametric MRI can differentiate between low- and high-grade bladder tumors with a high sensitivity and specificity of 93.3% and 98.3%, respectively. Conclusions Multiparametric MRI is an acceptable method for the preoperative detection and accurate staging of BC, with reasonable accuracy in differentiating between low- and high-grade BC.

A highly sensitive sensor. A sensor for detecting Zn2+, Cd2+, and Pb2+ ions simultaneously based on the square wave anodic stripping response at a bismuth antimony (Bi–Sb) nanocomposite electrode was developed.