We have analyzed the surface oxidation process of Pt nanoparticles that were uniformly dispersed on a glassy carbon electrode (Pt/GC), which was adopted as a model of a practical Pt/C catalyst for fuel cells, in N-purged 0.1 M HF solution by using angle-resolved, grazing-incidence X-ray photoelectron spectroscopy combined with an electrochemical cell (EC-ARGIXPS). Positive shifts in the binding energies of Pt 4f spectra were clearly observed for the surface oxidation of Pt nanoparticles at potentials E > 0.7 V vs RHE, followed by a bulk oxidation of Pt to form Pt(II) at E > 1.1 V. Three types of oxygen species (HO, OH, and O) were identified in the O 1s spectra. It was found for the first time that the surface oxidation process of the Pt/GC electrode at E < ca. 0.8 V (OH formation) is similar to that of a Pt(111) single-crystal electrode, whereas that in the high potential region (O formation) resembles that of a Pt(110) surface or polycrystalline Pt film.

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We report a case of massive ovarian edema after laparoscopic resection of an ovarian mass with suspicion of a large ovarian tumor.The patient, aged 30 years, was suspected of having a right ovarian mass and presented to our hospital for the first time. The right ovary was enlarged to 50 × 41 mm and appeared to have follicles surrounding the mass. There was no elevation of tumor markers, and hormone tests showed luteinizing hormone (LH) levels > follicle-stimulating hormone (FSH) levels. There were no findings that indicated malignancy, and the patient was placed under observation. Subsequently, laparoscopic surgery was performed in 2 years later due to right lower abdominal pain. The right ovary was enlarged to 5 cm in size. An incision was made, a clear exudate was observed, and the center of the ovary was a soft yellowish-white edematous tissue. A biopsy with a diameter of 2 cm was performed at the center of the ovary. No neoplastic changes were observed on pathological diagnosis, and a diagnosis of massive ovarian edema was made. The final diagnosis was made after laparoscopic surgery with observation and biopsy. This case demonstrates the importance of laparoscopy in the diagnosis of ovarian disorders and preservation of ovarian function.

Case: A 16-year-old Japanese female adolescent presented with left-sided lower abdominal pain. Ultrasonography and magnetic resonance imaging revealed a left adnexal cyst (5 cm). Her history was unremarkable except for a sliding inguinal hernia attributable to inguinal herniorrhaphy.We report a case of tubal occlusion and ovarian atrophy secondary to fallopian tube and ovarian ligation associated with inguinal herniorrhaphy.

The research and development of highly active cathode catalysts for the oxygen reduction reaction (ORR) is one of the most important subjects to achieve high efficiency in polymer electrolyte fuel cells (PEFCs). In order to understand the ORR mechanism and find clues to the design of high-performance cathode catalysts, it is essential to analyze surface the oxidation states of catalysts and the adsorbed oxygen species in the ORR. Recently, we have clarified the surface oxidation states of Pt polycrystalline and low-index single-crystal electrodes as a function of the electrode potential by using X-ray photoelectron spectroscopy combined with an electrochemical cell (EC–XPS).1 In practical PEFCs, however, Pt nanoparticles supported on carbon black have been employed as the anode and cathode catalysts. In the present research, we have prepared a model electrode of Pt nanoparticles supported on a carbon substrate and have examined the electronic structure of the Pt nanoparticles and the oxygen species adsorbed on the surface by using EC–XPS. Pt nanoparticles were prepared by a colloidal method,2 and dispersed on polished glassy carbon (GC). It was clarified by scanning electron microscopy (SEM) that Pt nanoparticles of ca. 3 nm diameter were well dispersed on the carbon substrate. We employed angle-resolved, grazing incidence X-ray photoelectron spectroscopy (AR-GIXPS), which is more surface-sensitive than conventional XPS, in order to analyze the small amount of Pt nanoparticles supported on the flat GC substrate. Figure 1 shows Pt 4f XP spectra of the Pt/GC model electrode after emersion from the 0.1 M HF solution at various electrode potentials. It was found that the peaks assigned to Pt 4f7/2 and 4f5/2 shifted to higher binding energies with increasing electrode potential. This peak shift can be ascribed to the surface core level shift induced by the surface oxidation of the Pt nanoparticles. At E > 1.1 V, peaks for bulk PtO, with binding energies of 73 and 77 eV, commenced to increase due to further oxidation of the Pt nanoparticles. Figure 2a shows O 1s XP spectra at the Pt/GC model electrode and a GC electrode (without any Pt) at 0.9 V, indicated by red and black lines, respectively. The O1s spectrum of the Pt/GC model electrode was found to include photoelectron signals attributed to oxygen species formed on the GC substrate, such as quinone and carboxyl groups. Then, we extracted the photoelectron signals originating from oxygen species adsorbed on the Pt nanoparticles by subtracting the O1s spectrum of the GC from that of the Pt/GC model electrode. Figure 2b shows the O1s difference spectrum for oxygen species adsorbed on the Pt nanoparticles. Thus, we succeeded in deconvoluting the difference spectrum into three components, H2Oad, OHad and Oad formed on the Pt nanoparticles. On the basis of the deconvoluted photoelectron intensities, it was found that H2Oad decreased with increasing electrode potential, while OHad increased. The Oad species was found to appear at E > 0.8 V. The onset potential of the OHad formation at the Pt/GC electrode was less positive than that for polycrystalline Pt, suggesting that the surface oxidation proceeded more easily at the Pt nanoparticle surfaces than at the polycrystalline surface. This work was supported by funds for the SPer-FC Project of NEDO, Japan   References 1 M. Wakisaka, H. Suzuki, S. Mitsui, H. Uchida, and M. Watanabe, Langmuir, 25, 1897 (2009). 2 M. Watanabe, M. Uchida, and S. Motoo, J. Electroanal. Chem., 199, 311 (1986). Figure 1