Patterns of radiotherapy practice for biliary tract cancer in Japan: results of the Japanese radiation oncology study group (JROSG) survey

Abstract Background The patterns of radiotherapy (RT) practice for biliary tract cancer (BTC) in Japan are not clearly established. Methods A questionnaire-based national survey of RT used for BTC treatment between 2000 and 2011 was conducted by the Japanese Radiation Oncology Study Group. Detailed information was collected for 555 patients from 31 radiation oncology institutions. Results The median age of the patients was 69 years old (range, 33–90) and 81% had a good performance status (0–1). Regarding RT treatment, 78% of the patients were treated with external beam RT (EBRT) alone, 17% received intraluminal brachytherapy, and 5% were treated with intraoperative RT. There was no significant difference in the choice of treatment modality among the BTC subsites. Many patients with EBRT were treated with a total dose of 50 or 50.4 Gy (~40%) and only 13% received a total dose ≥60 Gy, even though most institutions (90%) were using CT-based treatment planning. The treatment field consisted of the primary tumor (bed) only in 75% of the patients. Chemotherapy was used for 260 patients (47%) and was most often administered during RT (64%, 167/260), followed by after RT (63%, 163/260). Gemcitabine was the most frequently used drug for chemotherapy. Conclusions This study established the general patterns of RT practice for BTC in Japan. Further surveys and comparisons with results from other countries are needed for development and optimization of RT for patients with BTC in Japan. </jats:sec

Navigation for a Behavior-Based Autonomous Mobile Robot

We propose an implemented architecture that integrates possession of environmental knowledge into a reactive, behavior-based autonomous robot. As an alternative to hybrid combinations of behavior- and model-based systems, we present a fully behavior-based system that takes reactive, deliberate behavior. To get knowledge, a robot makes a the World Image, gradually constructed through experience as higher animals with self-organization do, without symbolic representation in associative memory. Since our World Image changes in direct relation to behavior, a robot navigates adaptively and reactively to its destination following a path plan based on the World Image of a dynamic environment. The path plan a robot makes is not a sequence of routes as in conventional planning, but flexible as in reactive planning. If a robot detects a failure, it reaches its destination without replanning or error recovery. Our approach makes practical a behavior-based robot already adapted to the real world.</jats:p

Development of Condition Monitoring System for Electric Resistance Spot Welding Used to Manufacture Railway Car Bodies

Stainless steel railway car bodies are assembled by joining the outer plates and the pillar materials using resistance spot welding. In recent years, more and more car bodies are being assembled using laser welding in addition to the resistance spot welding. For this laser welding system, we developed a condition monitoring system considering the processes before and after laser welding as a single system, and obtained and put into practical use an appropriate condition that suppresses spatter generation during laser welding. On the other hand, in resistance spot welding, the current, weld time, electrode load, and electrode tip shape are the main factors that determine the welding quality. Therefore, the configuration of the equipment is less complicated than that of laser welding system, and the condition monitoring is easier than that of the laser welding. In this study, by transferring the concept of the condition monitoring system developed for laser welding to resistance spot welding, we achieved a reduction of more than 60% in terms of electricity consumption and improved the appearance of the car body by optimizing the indentation shape. In addition to this technical achievement, we also present in this paper a case study showing the opportunity for innovation by restructuring the technological paradigm of the resistance spot welding in the production of stainless steel car body shells.</jats:p

Navigation Using Local Landmarks in a Corridor Environment

We propose a robot navigation using local landmarks and topological maps to make robots easy to use. To popularize the use of robots in the home and welfare institutions, robots must be easy for anyone to use. Conventional robots are generally expensive to implement due to extensive preparation such as providing maps with Cartesian coordinates and setting precise environmental landmarks called “setup costs [1].” For robots to navigate precisely, they must measure locations precisely, which may require sensors with high precision and sophisticated computing, e.g., to compensate for accumulated error caused by wheel slippage. Approaches without position coordinate make difficult, but we solve the problem using a user-friendly robot with inaccurate sensors and unsophisticated computing – “human” approach.</jats:p

Decision Making for a Mobile Robot Using Potential Function

We discuss decision making for a behavior-based robot with modules which determining robot action. The subsumption architecture (SA) arranges modules in layers, giving upper-layer module action priority over lower-layer modules. Although implementation is easy, results in many inefficient actions because upper-layer module are used regardless of other modules. We solve this problem by representing actions by Potential Function (PF), in which maximum votes are collected from modules. Using event-driven state transition, the robot decides its action with appropriate sets of modules changed based on the situation. We apply this to navigation tasks in a corridor and show simulation results. When we give a map and path designation to the robot, we use a handwriting map interface. We compare object-oriented design SA and PMF with our proposal and show how inefficient actions are reduced using our proposal.</jats:p

Phosphorus Localization and Its Involvement in the Formation of Concentrated Uranium in the Renal Proximal Tubules of Rats Exposed to Uranyl Acetate

Although the kidneys comprise a critical target of uranium exposure, the dynamics of renal uranium distribution have remained obscure. Uranium is considered to function physiologically in the form of uranyl ions that have high affinity for phosphate groups. The present study applied microbeam-based elemental analysis to precisely determine the distribution of phosphorus and uranium in the kidneys of male Wistar rats exposed to uranium. One day after a single subcutaneous injection of uranyl acetate (2 mg/kg), areas of concentrated phosphorus were scattered in the S3 segments of the proximal tubule of the kidneys, whereas the S3 segments in control rats and in rats given a lower dose of uranium (0.5 mg/kg) contained phosphorus without concentrated phosphorus. Areas with concentrated phosphorus contained uranium 4- to 14-fold more than the mean uranium concentration (126–472 vs. 33.1 ± 4.6 μg/g). The chemical form of uranium in the concentrated phosphorus examined by XAFS was uranium (VI), suggesting that the interaction of uranyl ions with the phosphate groups of biomolecules could be involved in the formation of uranium concentration in the proximal tubules of kidneys in rats exposed to uranium.</jats:p