• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.70.1-70.1
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• 2012

In-situ X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectroscopy studies of SOFC cathode materials will be discussed in this presentation. The mixed conducting perovskites (ABO3) containing rare and alkaline earth metals on the A-site and a transition metal on the B-site are commonly used as cathodes for solid oxide fuel cells (SOFC). However, the details of the oxygen reduction reaction are still not clearly understood. The information about the type of adsorbed oxygen species and their concentration is important for a mechanistic understanding of the oxygen incorporation into these cathode materials. XPS has been widely used for the analysis of adsorbed species and surface structure. However, the conventional XPS experiments have the severe drawback to operate at room temperature and with the sample under ultrahigh vacuum (UHV) conditions, which is far from the relevant conditions of SOFC operation. The disadvantages of conventional XPS can be overcome to a large extent with a "high pressure" XPS setup installed at the BESSY II synchrotron. It allows sample depth profiling over 2 nm without sputtering by variation of the excitation energy, and most importantly measurements under a residual gas pressure in the mbar range. It is also well known that the catalytic activity for the oxygen reduction is very sensitive to their electrical conductivity and oxygen nonstoichiometry. Although the electrical conductivity of perovskite oxides has been intensively studied as a function of temperature or oxygen partial pressure (Po2), in-situ measurements of the conductivity of these materials in contact with the electrolyte as a SOFC configuration have little been reported. In order to measure the in-plane conductivity of an electrode film on the electrolyte, a substrate with high resistance is required for excluding the leakage current of the substrate. It is also hardly possible to measure the conductivity of cracked thin film by electrical methods. In this study, we report the electrical conductivity of perovskite $La_{0.6}Sr_{0.4}CoO_{3-{\delta}}$ (LSC) thin films on yttria-stabilized zirconia (YSZ) electrolyte quantitatively obtained by in-situ IR spectroscopy. This method enables a reliable measurement of the electronic conductivity of the electrodes as part of the SOFC configuration regardless of leakage current to the substrate and cracks in the film.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6715-6717
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• 2015

Background: The purpose of this study was to provide epidemiological and histological data of thyroid cancers in Togo. Materials and Methods: This was a retrospective cross-sectional study of cases of thyroid cancers diagnosed from 2000 to 2014 (15 years) at the pathology laboratory of the Sylvanus Olympio Teaching Hospital of $Lom{\acute{e}}$. All cases of review of a thyroid sample (biopsies, surgical specimens) were collected from the data records of that laboratory. Results: Thyroid cancers represented 1.1% (7930cases) of all cancers registered during the study period. Mean age was $45.4{\pm}0.3$ years and the proportion of females was 78.3%. We identified 92.4% carcinomas and 7.6% lymphomas. Carcinomas were well differentiated in 80 cases and were dominated by the papillary type (47 cases). Metastasis was observed in 13% of patients. The pTNM classification evaluated in 18 cases showed a predominance of grade I (13 cases). Lymphomas were dominated by lymphoma diffuse large B-cell (5 cases). Conclusions: This study is the first global standard for thyroid cancer pathology in Togo. The high frequency of follicular form suggests an unrecognized iodine deficiency. The improvement of the technical platform of the LAP (immunohistochemistry) will increase the diagnosis of rare forms of thyroid cancer.

• The Korean Journal of Cytopathology
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• v.17 no.1
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• pp.51-55
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• 2006

The plasmacytoid variant is an extremely rare form of urothelial carcinoma in which the malignant cells resemble those of plasmacytoma. We report the cytologic features of 3 cases of this disorder. All 3 patients were male and presented with painless macroscopic hematuria. The voided urine cytology revealed a few scattered clusters of tumor cells in a bloody background. Each tumor cell had an abundant amount of cytoplasm that was clear or densely stained and characterized by eccentrically located nuclei. A histological examination of tissue obtained from a radical cystectomy confirmed the cytologic diagnosis in each 3 case, revealing a diffusely infiltrating tumor composed of round, noncohesive tumor cells demonstrating a high nuclear grade. These cells had infiltrated the tunica propria in 2 cases, but were limited to the submucosa in 1 case. The tumor cells were plasmacytoid in appearance, each demonstrating an eccentric nucleus and dense cytoplasm, as seen in the cytologic findings. All of the tumors were immunoreactive for pancytokeratin, CK7, CK20; negative for epithelial membrane antigen (EMA), leukocyte common antigen (LCA), kappa, lambda, and CD79a. Thus, it is important to consider the plasmacytoid variant of urothelial carcinoma in addition to plasmacytoma or lymphoma as a diagnosis when encountering plasmacytoid tumor cells in a voided urine sample.