Oxygen reduction reaction (ORR) catalytic activity of La0.67Sr0.33MnO3 epitaxial thin films was investigated in a KOH solution by using a rotating-disk electrode. We found that while the films exhibit ORR current, the current is not limited by oxygen transport resulting from the film electrode rotation and shows the large hysteresis against the potential sweep direction. This behavior is in stark contrast to the oxygen reduction reaction activity of an electrode ink made from LSMO bulk powder, whose ORR current is oxygen-transport limited. In situ synchrotron X-ray absorption spectroscopy also reveals that the valence state of Mn in the LSMO film surface is lowered under the reducing atmosphere caused by the overpotential. This indicates the overpotential-induced introduction of oxygen vacancies in the film surface. We also show that the ORR current of the LSMO films exposed to the reducing atmosphere is lowered than that of the original surface. These results indicate that the ORR catalytic activity of LSMO surfaces is strongly influenced by oxygen vacancies.

The selective etching of SiO2 on Si employing C4F8/H2 inductively coupled plasma (ICP) was studied based on measurements of radical and ion densities, flow rate and wall temperature. Since polymer films were not deposited when the reacter wall was heated to temperatures above 200° C, CF1 radical density at 200° C was one order higher than that at the wall temperature of 30° C. Thus both Si and SiO2 etch rates decreased rapidly with increasing H2 concentration in C4F8, and Si etching stopped at 15% H2. The etch stop was attributed to insufficient removal of polymer with a reduced amount of ions and was suppressed considerably by increasing the RF power to generate a large amount of ions. The use of poly-Si masks reduced the microloading effect in comparison to resist masks and a contact hole feature with 0.2 µ m size and aspect ratio of 6 was successfully obtained.

Although exfoliative dermatitis (erythroderma) secondary to malignancy is commonly associated with lymphomas or leukemias, coincident gastrointestinal (GI) malignancy and erythroderma is rare. The authors recently encountered a patient with gallbladder carcinoma presenting as erythroderma. A 77-yr-old Japanese man presented with a 3-mo history of erythematous eruptions with pruritus over almost the entire body. After confirming the diagnosis of erythroderma, asymptomatic gallbladder carcinoma was found. Further investigations detected no malignancies in other organs. An extended cholecystectomy was performed. Histologic examination of resected specimens revealed poorly differentiated adenocarcinoma with negative resection margins. The eruptions with pruritus resolved within 1 wk after the operation. This is the first report, to our knowledge, of coincident biliary malignancy and erythroderma. The experience of the current patient suggests that erythroderma secondary to GI malignancy may resolve spontaneously after curative resection of the tumor.

Articles you may be interested inComparison of laser-based and monochromator-based thermodynamic temperature measurements AIP Conf. Proc. 1552, 60 (2013); 10.1063/1.4819516 Short wavelength far infrared laser polarimeter with silicon photoelastic modulatorsa) Rev. Sci. Instrum. 79, 10E720 (2008); 10.1063/1.2957936 Noncontact nanosecond-time-resolution temperature measurement in excimer laser heating of Ni-P disk substrates Appl.Diffuse reflectance spectroscopy measurement of substrate temperature and temperature transient during molecular beam epitaxy and implications for low-temperature III-V epitaxy