Strong dependence of the inversion mobility of 4H and 6H SiC(0001)MOSFETs on the water content in pyrogenic re-oxidation annealing

The inversion channel mobility of 4H and 6H-SiC(0001) metal-oxide-semiconductor field-effect transistors (MOSFETs) has been evaluated for its dependence on the re-oxidation annealing (ROA) conditions in a wet oxidizing ambient. The wet ambient was supplied by the pyrogenic reaction of hydrogen and oxygen gas (pyrogenic ROA), where the water vapor content (ρ(H₂O)) was controlled by adjusting the hydrogen/oxygen gas flow rate. Not only the annealing temperature and the time, but also ρ(H₂O) are found to be the critical parameters for improving channel mobility. As a result, field-effect channel mobilities as high as 47 cm²/Vs for 4H and 95 cm²/Vs for 6H-SiC MOSFETs were achieved by pryrogenic ROA treatment with a ρ(H₂O) of 50%     

Photoisomerization of the azobenzenes included in Langmuir-Blodgett films of cyclodextrins

A new type of photochemical Langmuir-Blodgett (LB) film containing azobenzenes (p-phenylazobenzoic acid (PAB), methyl red (MR) and methyl orange (MO)) without long alkyl chains was prepared by the host-guest interaction with an amphiphilic cyclodextrin derivative. The azobenzenes in the LB film of the host- guest complex exhibited an excellent cis-trans photoisomerization, while trans-to- cis photoisomerization was restricted for LB films of long chain azobenzene derivatives alone. The cavity of cyclodextrin provides a favourable environment for the photochemical reaction leading to an increase in the molecular area in the rigid LB film. The half-life times of cis isomers of PAB, MR and MO in the host-guest complex LB films were 35 h, 55 s and 13 min respectively at 20°C.     

Cost effectiveness analysis of FDG-PET in the differential diagnosis and staging of lung cancer in Japan

Several studies have shown that FDG-PET is more accurate than CT for the differential diagnosis and for the staging of lung cancer. We have analyzed potential effect of FDG-PET on the medical cost for the management of patients suspected of lung cancer. In the differential diagnosis, chest CT plus FDG-PET protocol reduced the number of bronchofiberscope (BFS) and biopsy by one fourth of that in the conventional protocol using CT alone. PET protocol reduced unnecessary examinations for the patients of benign disease, however, it increased the total cost of examinations by 25% due to the higher cost of PET than that of BFS and biopsy in Japan. In the staging of lung cancer, PET protocol improved accuracy of staging, reduced unnecessary surgery by 67%, and showed a saving of the cost of examination by 5%, and the total medical cost by 2.5% compared to that in the conventional protocol using CT, brain MRI, and bone scan. Conclusion: Use of FDG-PET for the staging may contribute to the improvement of patient management of lung cancer patients also to the saving of the medical cost.     

Influence of chemotherapy on FDG uptake by human cancer xenografts in nude mice

This study evaluated the use of PET with 18F-2-deoxy-2-fluoro-D-glucose (18F-FDG) for monitoring chemotherapy effects, using a human cancer xenograft (poorly differentiated human gastric cancer) in vivo model. METHODS: Tumor 18F-FDG uptakes and sizes were measured after administrating mitomycin (MMC), cisplatin (CDDP) and adriamycin (ADR) to xenograft-bearing nude mice and compared with 18F-FDG tumor uptake and tumor size in a non-therapy group. The correlation between the uptake and size was also assessed. RESULTS: The largest reduction in tumor size after chemotherapy occurred in the MMC administered group, followed by the CDDP case, with no reduction in the ADR group as compared to the controls. Fluorine-18-FDG tumor uptake after chemotherapy was also decreased in the MMC and CDDP groups, in that order, but not in the ADR case. With MMC and CDDP, size reduction became significant on Days 8 or 11, whereas 18F-FDG tumor uptake had already been decreased on Days 3 or 7. CONCLUSION: Fluorine-18-FDG uptake decreases in parallel to the efficacy of anticancer agents and correlates with subsequent morphologic changes. We conclude that 18F-FDG PET tumor images are indeed useful for monitoring the effects of cancer chemotherapy.     

Pulmonary myxoid leiomyosarcoma

A primary myxoid leiomyosarcoma arising from the peripheral bronchus of the right middle lobe was removed from a 20 year old man and examined by immunohistochemistry and electron microscopy. The tumor was well circumscribed, yellow-whitish focal polypoid growth into the bronchial lumen and consisted of spindle cells with abundant myxoid substance in the stroma. Intrapulmonary metastasis, invasion to the bronchial wall and a few mitotic figures were found. Immunohistochemically, several, but not all, tumor cells were positive against anti-vimentin, anti-S-100 protein, anti-myosin and anti-muscle specific actin. Ultrastructurally, tumor cells had thin filaments with dense bodies, pinocytic vesicles and discontinuous basal lamina. These findings indicate a myoxoid variant of leiomyosarcoma arising from mesenchyme in the peribronchial area.     

Anteroaxillary thoracotomy facilitates the use of retrograde cerebral perfusion in distal aortic arch reconstruction

Anteroaxillary thoracotomy in a 45-degree position provides an ideal view of the distal aortic arch and also makes direct superior vena caval cannulation possible for retrograde cerebral perfusion. This approach is especially useful in cases in which retrograde cerebral perfusion is indicated as an adjunct to deep hypothermic circulatory arrest in repair of the distal aortic arch.     

Distributed computing using autonomous objects

Most existing distributed systems are structured as statically compiled processes communicating with each other via messages. The system's intelligence is embodied in the processes, while the messages contain simple, passive pieces of information. This is referred to as the communicating objects paradigm. In the autonomous objects paradigm, a message has its own identity and behavior. It decides at runtime where it wants to propagate and what tasks to perform there; the nodes become simply generic interpreters that enable messages to navigate and compute. In this scenario, an application's intelligence is embodied in and carried by messages as they propagate through the network. The autonomous objects paradigm is more flexible than the communicating objects paradigm because it allows developers to change the program's behavior after it has started to run. We based our system, MESSENGERS, on autonomous objects, and intended it for the composition and coordination of concurrent activities in a distributed environment. It combines powerful navigational capabilities found in other autonomous objects based systems with efficient dynamic linking mechanisms supported by some new programming languages, like Java