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Perianal extramammary Paget's disease, Bowen's disease, and squamous cell carcinoma are three entities that are very rarely reported. Overall, it is generally accepted that wide surgical excision is adequate treatment except under certain circumstances. Consideration has to be given to invasiveness, metastatic potential, multicentricity, and tendency to recur. We describe four patients who, following unsuccessful multiple attempts at achieving microscopically clear margins with surgical excision, were treated at Roswell Park Cancer Institute with photodynamic therapy with a surface illumination method. With a minimum follow-up of 6 months (more than 1 year in three patients), there have been no recurrences to date.

A B S T R A C TPatterned cathode/electrolyte interfaces formed by a hexagonal array of ∼22 μm deep wells with 24 μm lattice parameter have been prepared by pulsed laser machining to enlarge the contact surface and, consequently, to reduce the cathode polarization of Solid Oxide Fuel Cells. These new interfaces have been tested in YSZ-LSM/ YSZ/YSZ-LSM symmetrical cells, where the cathode is deposited by dip-coating. Appropriate ceramic suspensions have been formulated to penetrate into deep wells without presenting interfacial delamination after sintering. We analyse their applicability by comparing their rheology with the microstructure and electrochemical performance of the cells. The activation component of the polarization resistance is reduced by ∼50% using ethanol-based suspensions with 20 wt% solids loading, although the gas diffusion component increases due to excessive densification. Alternative ceramic suspensions with 17.5 wt% solids loading provide optimum electrode gas diffusion but lower activation components, resulting in an overall decrease of ∼20% in polarization resistance.

By laser machining we have prepared thin and self-supported yttria stabilized zirconia (YSZ) electrolytes that can be used in electrolyte-supported Solid Oxide Fuel Cells for reducing the operation temperature. The membranes, which are supported by thicker areas of the same material, have an active area of ~20 µm in thickness and up to 8 mm in diameter. Buckling limits the maximum size of the thin areas to below 1 mm, the overall effective active area being formed by multiple thin areas bounded by ribs. ElectronBackscattering Diffraction experiments determined that there are not significant strains inside the membranes and that the heat-affected zone is confined to a shallow layer of ~1-2 µm. The bending strength of the membranes decreases by ~26% as a result of the surface microcracking produced by the laser machining. The membranes have a roughness of ~2.5 µm and are coated by a layer of nanoparticles produced by the laser ablation. This coating and small roughness is not detrimental for the cathodic polarization of the cells. Conversely, the cathode polarization resistance decreases ~5% in the 650-850 ºC temperature range.

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