The bladder, the largest smooth-muscle organ in the human body, is responsible for urine storage and micturition. P63, a homolog of the p53 tumor-suppressor gene, is essential for the development of all stratified epithelia, including the bladder urothelium. The N-terminal truncated isoform of p63, ⌬Np63, is known to have anti-apoptotic characteristics. We have established that ⌬Np63 is not only the predominant isoform expressed throughout the bladder, but is also preferentially expressed in the ventral bladder urothelium during early development. We observed a host of ventral defects in p63 -/-embryos, including the absence of the abdominal and ventral bladder walls. This number of ventral defects is identical to bladder exstrophy, a congenital anomaly exhibited in human neonates. In the absence of p63, the ventral urothelium was neither committed nor differentiated, whereas the dorsal urothelium was both committed and differentiated. Furthermore, in p63 -/-bladders, apoptosis in the ventral urothelium was significantly increased. This was accompanied by the upregulation of mitochondrial apoptotic mediators Bax and Apaf1, and concurrent upregulation of p53. Overexpression of ⌬Np63␥ and ⌬Np63␤ in p63 -/-bladder primary cell cultures resulted in a rescue, evidenced by significantly reduced expressions of Bax and Apaf1. We conclude that ⌬Np63 plays a crucial anti-apoptotic role in normal bladder development.

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Ruthenium (Ru) chemical mechanical planarization (CMP) with a slurry using sodium periodate (NaIO 4 ) as an oxidizer was carried out as a function of pH. The Ru polishing rate was highest at pH 7 and decreased as the pH decreased or increased. In addition, a similar trend in the corrosion current density as a function of pH was found. Two equivalent circuit models were proposed to explain the electrochemical impedance spectroscopy (EIS) results of Ru in NaIO 4 solution as a function of pH. From results of EIS, we found that the Ru film had a lowest charge transfer resistance in a neutral region than that in an acidic or alkaline region. This different charge transfer resistance of the Ru film as a function of pH resulted from the different surface composition of Ru oxide species, which was analyzed with X-ray photoelectron spectroscopy. Finally, we briefly derived a series of reaction equations between Ru and NaIO 4 on the basis of the above results and discussion.