31 results on '"Ryosuke Okada"'
Search Results
2. When to Target Customers? Retention Management using Dynamic Off-Policy Policy Learning
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Ryuya Ko, Kosuke Uetake, Kohei Yata, and Ryosuke Okada
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
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3. A REPORT ON THE INFORMATION SUPPORT ACTIVITIES USING GIS IN VOLUNTEER CENTER OF AREAS STRICKEN BY THE HEAVY RAIN EVENT OF JULY 2018
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Hisanori Yagi, Kazuya Ishibashi, Kenta Tanaka, Takahiro Tanaka, Makoto Yokoyama, Machiko Honda, Shota Tamura, Ami Ishibashi, Remon Kanai, Izumi Akamatsu, Taiki Oryoji, Ryosuke Okada, Shuhei Ota, and Aoi Yamada
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Geography ,Event (relativity) ,Architecture ,Center (algebra and category theory) ,Building and Construction ,Information support ,Cartography - Published
- 2019
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4. Evaluation of the accuracy and clinical practicality of a calculation system for patient positional displacement in carbon ion radiotherapy at five sites
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Ryosuke Okada, Takayoshi Ishii, Takashi Nakano, Yoshiki Kubota, Saki Souda, Hayato Hayashi, Tatsuya Ohno, Mutsumi Tashiro, Masami Torikoshi, Satoshi Abe, and Tatsuaki Kanai
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initial position dependence ,Lung Neoplasms ,automatic system ,Radiography ,Heavy Ion Radiotherapy ,Radiotherapy Setup Errors ,Imaging phantom ,Standard deviation ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Region of interest ,mental disorders ,Radiation Oncology Physics ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Radiation treatment planning ,Instrumentation ,Digital radiography ,ROI size dependence ,Radiation ,Phantoms, Imaging ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Liver Neoplasms ,Head and neck cancer ,carbon ion radiotherapy ,Cancer ,Radiotherapy Dosage ,patient positioning ,Prognosis ,medicine.disease ,Pancreatic Neoplasms ,Head and Neck Neoplasms ,030220 oncology & carcinogenesis ,Tomography, X-Ray Computed ,business ,Nuclear medicine ,psychological phenomena and processes - Abstract
Purpose We developed a system for calculating patient positional displacement between digital radiography images (DRs) and digitally reconstructed radiography images (DRRs) to reduce patient radiation exposure, minimize individual differences between radiological technologists in patient positioning, and decrease positioning time. The accuracy of this system at five sites was evaluated with clinical data from cancer patients. The dependence of calculation accuracy on the size of the region of interest (ROI) and initial position was evaluated for clinical use. Methods For a preliminary verification, treatment planning and positioning data from eight setup patterns using a head and neck phantom were evaluated. Following this, data from 50 patients with prostate, lung, head and neck, liver, or pancreatic cancer (n = 10 each) were evaluated. Root mean square errors (RMSEs) between the results calculated by our system and the reference positions were assessed. The reference positions were manually determined by two radiological technologists to best‐matching positions with orthogonal DRs and DRRs in six axial directions. The ROI size dependence was evaluated by comparing RMSEs for three different ROI sizes. Additionally, dependence on initial position parameters was evaluated by comparing RMSEs for four position patterns. Results For the phantom study, the average (± standard deviation) translation error was 0.17 ± 0.05, rotation error was 0.17 ± 0.07, and ΔD was 0.14 ± 0.05. Using the optimal ROI size for each patient site, all cases of prostate, lung, and head and neck cancer with initial position parameters of 10 mm or under were acceptable in our tolerance. However, only four liver cancer cases and three pancreatic cancer cases were acceptable, because of low‐reproducibility regions in the ROIs. Conclusion Our system has clinical practicality for prostate, lung, and head and neck cancer cases. Additionally, our findings suggest ROI size dependence in some cases.
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- 2018
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5. A Case of Bilobular Spontaneous Biloma Associated with Acalculous Cholecystitis
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Akihiko Tsuchida, Kazuhiko Kasuya, Hirokatsu Ichimiya, Ryosuke Okada, Yuichi Nagakawa, Mitsuru Watanabe, and Kenji Katsumata
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medicine.medical_specialty ,business.industry ,Internal medicine ,Medicine ,Acalculous cholecystitis ,business ,Gastroenterology - Published
- 2017
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6. Distribution of Minerals in Young and Mature Leaves of Different Leaf Vegetable Crops Cultivated in a Field
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Eriko Maejima, Takuro Shinano, Aiko Yamauchi, Toshihiro Watanabe, Masaru Urayama, Ryosuke Okada, Mitsuru Osaki, and Masako Owadano
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food.dish ,business.industry ,Nitrogen assimilation ,fungi ,food and beverages ,Distribution (economics) ,Crown daisy ,Vegetable crops ,Biology ,food ,Botany ,Glebionis coronaria ,Phloem transport ,business - Abstract
At least 17 elements are known to be essential for plants; however, plants also absorb and accumulate various nonessential elements. Plants re-translocate different elements, including essential and nonessential elements, with differing efficiencies from mature to young developing organs via the phloem transport, resulting in different distributions of minerals in these organs. Therefore, in this study, we analyzed the concentrations of 23 elements in young and mature leaves of different leaf vegetable crops to comprehensively understand the mineral dynamics in plants. The allocation profiles of minerals in leaves of varying ages differed among species. For example, a higher molybdenum allocation profile was observed in young crown daisy ( Glebionis coronaria ) leaves, which might be related to the efficient nitrate assimilation in young leaves of this species. Thus, this study provides a new insight into the mineral uptake and transport mechanisms in plants.
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- 2016
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7. Ignition Characteristics of 2,5-Dimethylfuran Compared with Gasoline and Ethanol
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Naozumi Isobe, Yoshiki Fujisawa, Ryosuke Okada, Mitsuru Konno, Kotaro Tanaka, Kota Sato, and Hiroya Okada
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Ignition system ,chemistry.chemical_compound ,Ethanol ,Materials science ,chemistry ,law ,2,5-Dimethylfuran ,Octane rating ,Organic chemistry ,General Medicine ,Gasoline ,law.invention - Published
- 2015
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8. Development of an automatic evaluation method for patient positioning error
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Takayoshi Ishii, Tatsuya Ohno, Takashi Nakano, Ayaka Shinohara, Satoshi Abe, Tatsuaki Kanai, Yoshiki Kubota, Mutsumi Tashiro, Saki Souda, and Ryosuke Okada
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Male ,Mean squared error ,Computer science ,Radiography ,positioning error ,Radiotherapy Setup Errors ,Residual ,Imaging phantom ,Pelvis ,Automation ,Image Interpretation, Computer-Assisted ,mental disorders ,Radiation Oncology Physics ,Humans ,Radiology, Nuclear Medicine and imaging ,Computer vision ,Instrumentation ,Digital radiography ,Radiation ,Pixel ,Phantoms, Imaging ,business.industry ,Prostatic Neoplasms ,Isocenter ,Radiotherapy Dosage ,block‐matching ,patient positioning ,Evaluation function ,Artificial intelligence ,Tomography, X-Ray Computed ,business ,Algorithms ,psychological phenomena and processes ,measuring - Abstract
Highly accurate radiotherapy needs highly accurate patient positioning. At our facility, patient positioning is manually performed by radiology technicians. After the positioning, positioning error is measured by manually comparing some positions on a digital radiography image (DR) to the corresponding positions on a digitally reconstructed radiography image (DRR). This method is prone to error and can be time‐consuming because of its manual nature. Therefore, we propose an automated measuring method for positioning error to improve patient throughput and achieve higher reliability. The error between a position on the DR and a position on the DRR was calculated to determine the best matched position using the block‐matching method. The zero‐mean normalized cross‐correlation was used as our evaluation function, and the Gaussian weight function was used to increase importance as the pixel position approached the isocenter. The accuracy of the calculation method was evaluated using pelvic phantom images, and the method's effectiveness was evaluated on images of prostate cancer patients before the positioning, comparing them with the results of radiology technicians' measurements. The root mean square error (RMSE) of the calculation method for the pelvic phantom was 0.23±0.05 mm. The coefficients between the calculation method and the measurement results of the technicians were 0.989 for the phantom images and 0.980 for the patient images. The RMSE of the total evaluation results of positioning for prostate cancer patients using the calculation method was 0.32±0.18 mm. Using the proposed method, we successfully measured residual positioning errors. The accuracy and effectiveness of the method was evaluated for pelvic phantom images and images of prostate cancer patients. In the future, positioning for cancer patients at other sites will be evaluated using the calculation method. Consequently, we expect an improvement in treatment throughput for these other sites. PACS number: 87
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- 2015
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9. Development of mobile gestural control system of a vehicle
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Shoshiro Hatakeyama, Masami Iwase, and Ryosuke Okada
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body regions ,business.industry ,Computer science ,Obstacle ,Control system ,Path (graph theory) ,Robot ,Computer vision ,Development (differential geometry) ,Artificial intelligence ,Position control system ,business ,Intersection (aeronautics) - Abstract
The purpose of this study is development of Mobile Gestural Control System of a Vehicle. The designated coordinate was estimated from the intersection of the location information and the floor of the elbow and wrist. Position control system for moving the vehicle indicated coordinate was designed. When there is an obstacle on the path of the robot, vehicle avoid the obstacle by potential method.
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- 2017
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10. The Estimation Method of Force by Using Kinect Camera
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Shoshiro Hatakeyama, Ryosuke Okada, and Masami Iwase
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Hardware_MEMORYSTRUCTURES ,Evaluation system ,Computer science ,Myoelectric signal ,Torque ,Biosignal ,Simulation - Abstract
The purpose of this paper is an estimation of driving torque by using an external sensor. This paper deals with an estimation method of driving torque and physical parameters. This research have been estimated the driving torque of each joints as the force. Future, this research will design an estimation system of a myoelectric signal using an external sensor. Moreover, we aim to design an evaluation system of the ability to exercise using obtained biosignal.
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- 2017
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11. Potential Pitfalls of a Fiducial Marker-matching Technique in Carbon-ion Radiotherapy for Lung Cancer
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Jun-ichi Saitoh, Yoshiki Kubota, Makoto Sakai, Takashi Nakano, Takanori Abe, Shintaro Shiba, Tatsuya Ohno, Daisuke Irie, Katsuyuki Shirai, and Ryosuke Okada
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Lung Neoplasms ,medicine.medical_treatment ,Heavy Ion Radiotherapy ,Dose distribution ,Patient Positioning ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Fiducial Markers ,Predictive Value of Tests ,Carcinoma, Non-Small-Cell Lung ,Humans ,Medicine ,Lung cancer ,Neoplasm Staging ,Retrospective Studies ,Stage I Lung Cancer ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Radiation field ,Radiotherapy Dosage ,medicine.disease ,Tumor Burden ,Gross tumor volume ,Radiation therapy ,Treatment Outcome ,ROC Curve ,Area Under Curve ,030220 oncology & carcinogenesis ,Carbon Ion Radiotherapy ,Tomography, X-Ray Computed ,business ,Fiducial marker ,Nuclear medicine - Abstract
Background/aim To analyze the accuracy of patient positioning and dose distribution quality using a fiducial marker-matching technique in carbon-ion radiotherapy (C-ion RT) for stage I lung cancer. Patients and methods Thirteen patients with 26 fiducial markers and 104 radiation fields were examined. Change in the fiducial marker position coordinates from the gross tumor volume center (Δm), and change in the water-equivalent path length of the chest wall (ΔWEL) were measured in each radiation field. Criterion for an acceptable change in dose distribution was defined as the percentage of D95 (%D95) at gross tumor volume greater than 90% of the prescribed dose. Results Thirteen radiation fields (12.5%) were classified as unacceptable. Δm and ΔWEL had significant negative correlations with %D95 and thus were significant factors related to unacceptable irradiation fields. Conclusion Patient positioning using a fiducial marker-matching technique resulted in 12.5% of radiation fields demonstrating unacceptable degradation due to Δm and ΔWEL.
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- 2017
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12. Robustness of patient positioning for interfractional error in carbon ion radiotherapy for stage I lung cancer: Bone matching versus tumor matching
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Ryosuke Okada, Takashi Nakano, Daisuke Irie, Katsuyuki Shirai, Yoshiki Kubota, Masami Torikoshi, Jun-ichi Saitoh, Makoto Sakai, and Tatsuya Ohno
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Male ,medicine.medical_specialty ,Matching (statistics) ,Lung Neoplasms ,Radiography ,Planning target volume ,Patient positioning ,Heavy Ion Radiotherapy ,Bone and Bones ,Patient Positioning ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Carcinoma, Non-Small-Cell Lung ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Radiation treatment planning ,Lung cancer ,Lung ,Aged ,Aged, 80 and over ,Stage I Lung Cancer ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Radiotherapy Dosage ,Hematology ,Middle Aged ,medicine.disease ,Surgery ,Oncology ,030220 oncology & carcinogenesis ,Carbon Ion Radiotherapy ,Female ,business ,Nuclear medicine ,Tomography, X-Ray Computed - Abstract
Background and purpose Patient positioning was compared by tumor matching (TM) and conventional bony structure matching (BM) in carbon ion radiotherapy for stage I non-small cell lung cancer to evaluate the robustness of TM and BM in determining interfractional error. Material and methods Sixty irradiation fields were analyzed. Computed tomography (CT) images acquired before treatment initiation for confirmation (Conf-CT) were obtained under the same settings as the treatment planning CT images and used to evaluate both positioning methods. The dose distributions were recalculated for Conf-CT using both BM and TM, and the dose–volume histogram parameters [V 95% of clinical target volume, V 5Gy(RBE) of normal lung, and acceptance ratio (ratio of cases with V 95% > 95%)] were evaluated. The required margin, which in 90% of cases achieved the acceptable condition, was also examined. Results Using BM and TM, the median V 95% was 98.93% and 100% ( p 5Gy(RBE) was 135.9 and 125.8 ( p = 0.694), respectively. The estimated required margins were 7.9 and 3.3 mm and increased by 53.9% and 2.5% of V 5Gy(RBE) , respectively, compared with planning. Conclusions TM ensured a better dose distribution than did BM. To enable TM, volumetric imaging is crucial and should replace 2D radiographs for carbon therapy of stage I lung cancer.
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- 2017
13. Microscopic Structure of K-Doped Organic Monolayers
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Masahiro Yano, Yuri Hasegawa, Megumi Endo, Yoichi Yamada, Ryosuke Okada, Masahiro Sasaki, and Ryosuke Shimizu
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Chemistry ,Inorganic chemistry ,Doping ,Bioengineering ,Surfaces and Interfaces ,Condensed Matter Physics ,Alkali metal ,Surfaces, Coatings and Films ,law.invention ,Mechanics of Materials ,law ,Monolayer ,Scanning tunneling microscope ,Biotechnology - Published
- 2014
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14. Alkali-Metal Adsorption on the Monolayer of Coronene
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Yuri Hasegawa, Yoichi Yamada, Masahiro Yano, Ryosuke Okada, Masahiro Sasaki, and Megumi Endo
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chemistry.chemical_compound ,Adsorption ,Materials science ,chemistry ,Inorganic chemistry ,Monolayer ,Alkali metal ,Coronene - Published
- 2013
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15. The Impact of Gadolinium-based Contrast Agent for Carbon Ion Radiotherapy
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Makoto Sakai, Ryosuke Okada, Yoshiki Kubota, Yusuke Itabashi, Nao Mogi, Yasuhiro Fukushima, Takashi Nakano, Tatsuya Ohno, and Takayuki Sutou
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Adult ,Male ,Materials science ,Gadolinium ,medicine.medical_treatment ,media_common.quotation_subject ,chemistry.chemical_element ,Contrast Media ,Heavy Ion Radiotherapy ,Stopping power ,030218 nuclear medicine & medical imaging ,Gadolinium-based Contrast Agent ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Contrast (vision) ,Humans ,Irradiation ,media_common ,Aged ,Aged, 80 and over ,Carbon Isotopes ,Particle therapy ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,General Medicine ,Middle Aged ,Image Enhancement ,chemistry ,030220 oncology & carcinogenesis ,Carbon Ion Radiotherapy ,Female ,Nuclear medicine ,business ,Tomography, X-Ray Computed - Abstract
Purpose The contrast agent used in the diagnostic department has high atomic numbers and might influence dose deposition in the particle therapy. In particular, the influence of gadolinium-based (Gd) contrast agent on range in carbon ion radiotherapy has not yet been evaluated. For this reason, we avoid carbon treatment and planning computed tomography (CT) acquisition on days when the contrast-enhanced magnetic resonance image (MRI) is performed. In this study, we evaluated the time required for this beam range effect to vanish by evaluating the temporal changes in the CT values after an enhanced MRI as well as the stopping power of Gd solution. Materials and methods Two types of diluted solutions with Gd contrast agent were used for comparing their transferred stopping power (TSP) and measured stopping power (MSP). The TSP was calculated with a CT value to stopping power ratio table that was created previously. Additionally, to evaluate in vivo attenuation, we measured the CT values in the renal pelvis from the CT images with and without contrast agent for 73 patients. Results The maximum difference between the TSP and MSP was 85%. The difference between the TSP after 4 hours and the TSP with non-enhanced cases was less than 1%. Moreover, the difference between the MSP after 1 hour and the MSP with non-enhanced cases was less than 0.1%. Conclusion It was found that the impact of Gd contrast agent can be neglected 1 hour after administration for carbon beam irradiation and 4 hours after for planning the CT image acquisition.
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- 2016
16. A Novel Evaluation Method for Displacement between Carbon Beam Axis and Positioning X-ray Axis Using an Imaging Plate
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Takayuki Sutou, Hikaru Souda, Tatsuya Ohno, Ryosuke Okada, Eri Takeshita, Takayoshi Ishii, Tatsuaki Kanai, Yuji Kurosawa, Takashi Nakano, Yoshiki Kubota, and Yoshiaki Ohashi
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Materials science ,business.industry ,X-Rays ,X-ray ,chemistry.chemical_element ,General Medicine ,Multi leaf collimator ,Displacement (vector) ,Carbon ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Optics ,Lead plate ,chemistry ,030220 oncology & carcinogenesis ,Evaluation methods ,Carbon Ion Radiotherapy ,Carbon beam ,business ,Technology, Radiologic - Abstract
PURPOSE We developed an evaluation method for easily calculating displacement directly between the carbon beam axis and positioning X-ray axis. METHODS A verification image was acquired by irradiating an imaging plate with a carbon beam and X-ray. The X-ray passed through a lead plate inserted in the range compensator holder. The displacement was calculated on the verification image from the center of a wire irradiated with carbon using a multi leaf collimator (MLC) and a wire irradiated with X-ray also using MLC. The accuracy of the method was evaluated by moving the carbon beam axis, the X-ray axis, and the setup angle. The weekly changes of vertical and lateral beams in all rooms were also evaluated. RESULTS The displacements of the carbon beam axis and the setup angle did not influence the calculation results, whereas the displacement of the X-ray axis did (R=0.999). The displacements including weekly changes were all less than 1.00 mm. CONCLUSION An evaluation method for calculating the displacement directly and simply between the carbon beam axis and positioning X-ray axis was developed and verified. The weekly changes of displacement between axes were evaluated to be acceptable at our facility.
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- 2016
17. Critical concentrations of superconductor to insulator transition in (1 1 1) and (0 0 1) CVD boron-doped diamond
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Hitoshi Ishiwata, M. Watanabe, Yoshihiko Takano, Takahide Yamaguchi, Shingo Iriyama, Ryosuke Okada, Hiroshi Kawarada, S. Kitagoh, and Akihiro Kawano
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Superconductivity ,Materials science ,Analytical chemistry ,Energy Engineering and Power Technology ,Diamond ,chemistry.chemical_element ,Chemical vapor deposition ,engineering.material ,Condensed Matter Physics ,Ion source ,Electronic, Optical and Magnetic Materials ,chemistry ,Plasma-enhanced chemical vapor deposition ,engineering ,Electrical and Electronic Engineering ,Metal–insulator transition ,Boron ,Microwave - Abstract
The superconducting transition temperatures (TC) of (1 1 1) and (0 0 1) boron-doped diamond films deposited by microwave plasma assisted chemical vapor deposition (MPCVD) are investigated in the wide boron concentration range of 1 × 1020 − 1 × 1022 cm−3. The critical boron concentrations of superconductor to insulator transition in (1 1 1) and (0 0 1) films are 3 × 1020 cm−3. TC in (1 1 1) films does not have the tendency to saturate up to 1 × 1022 cm−3, while TC in (0 0 1) films saturates.
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- 2010
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18. A Case of Post-Esophagectomy Chylothorax Successfully Treated with Octreotide after the Failure of Thoracic Duct Ligation in an Esophageal Cancer Patient
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Fumiaki Kato, Yoshiaki Suzuki, Yoshihiro Yasuda, Toshiaki Aoki, Makoto Takagi, Tatsuya Aoki, Ryosuke Okada, Daisuke Matsuda, Jeong Sik Lee, and Tetsuo Sumi
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medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Gastroenterology ,Octreotide ,Chylothorax ,Esophageal cancer ,medicine.disease ,Thoracic duct ligation ,Surgery ,Esophagectomy ,medicine ,Radiology ,business ,medicine.drug - Abstract
症例は42歳の男性で, 胸部中部進行食道癌に対し術前化学放射線療法を施行後, 右開胸開腹食道亜全摘, 3領域リンパ節郭清 (胸管温存) を行った. 第3病日より胸腔ドレーンの排液が急増し, 翌日経腸栄養を開始したところ排液が白濁したため乳糜胸と診断した. 同日総排液量は1,800mlに達し循環動態に影響が出たため手術を施行した. 下縦隔で胸管をクリッピングしたが上縦隔からの乳糜漏出は停止せず, 上縦隔左側を展開し胸管の乳糜漏出部を確認し, その足側をクリッピングして漏出を停止できた. しかし, 翌日にはドレーンから再度多量の乳糜流出が認められたため, オクトレオチド50μg×3回/日の間歇皮下投与を試みた. 2日目から排液は著明に減少し, 計8日間漸減投与し中止としたが乳糜漏の停止が確認され退院できた. 食道癌術後の乳糜胸には難渋することがあるが, オクトレオチド間歇皮下投与は, 副作用も認められず試みる価値があるものと思われた.
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- 2006
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19. A CASE OF RECURRENT GASTRIC CANCER WITH LEUKEMOID REACTION-ANALYSIS OF G-CSF AND IL-6 PRODUCING
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Tatsuya Aoki, Tomoko Katagiri, Ryosuke Okada, Tatsuto Ashizawa, Tetsuo Sumi, and Shigeru Masuda
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biology ,business.industry ,Immunology ,medicine ,biology.protein ,Recurrent gastric cancer ,Leukemoid reaction ,medicine.disease ,business ,Interleukin 6 - Abstract
腫瘍はさまざまなサイトカインを産生し,その進展を促すとともに随伴症状を呈する.今回,胃癌術後類白血病反応を呈したG-CSF, IL-6を産生する再発例を経験した.症例は55歳,男性.平成13年12月胃全摘術が施行され,翌年11月より39°C台の発熱, WBC, CRP, CEA, CA19-9などの著明な上昇を認めた.骨髄検査では,反応性の骨髄過形成以外異常所見はみられず血液疾患は否定された.左腎上極外側に6×4cmの腫瘤を認め,組織学的に胃癌の再発腫瘍と診断された.また,腫瘍の細胞質にG-CSF, IL-6の陽性所見を認め各血清値 (242.0pg/ml, 60.3pg/ml) への反映が示唆された.病状はしだいに進行し類白血病反応を呈するとともに,癌性悪液質のため平成15年1月永眠された.死亡前の白血球数114,960/μl, CRP 16.18mg/dl, CEA 229.79ng/ml, CA19-9 491.57U/mlまで上昇した.術後の急速な進展と生体反応は, G-CSFおよびIL-6の強い影響が示唆された.
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- 2005
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20. A Massive Esophageal Intramural Metastasis of Gastric Cardia Cancer Involving Submucosa : A Case Reprort
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Hidenori Tomioka, Tatsuto Ashizawa, Makoto Mochizuki, Yoshiaki Suzuki, Makoto Takagi, Toshiaki Aoki, Ryosuke Okada, Tatsuya Aoki, Tatsuyuki Yamazaki, and Tetsuo Sumi
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Oncology ,medicine.medical_specialty ,medicine.anatomical_structure ,business.industry ,Internal medicine ,Submucosa ,medicine ,Gastric Cardia Cancer ,medicine.disease ,business ,Gastroenterology ,Metastasis - Published
- 2004
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21. Evaluation of the Efficacy of Metallic Stent for Inoperable Esophageal Cancer in Comparison with Plastic Prosthesis or Bypass Surgery
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Yoshiaki Osaka, Takashi Ogata, Yasuhisa Koyanagi, Motoo Shinohara, Shigeru Sato, Ryosuke Okada, Tatsuya Aoki, and Yu Takagi
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medicine.medical_specialty ,Bypass surgery ,business.industry ,medicine.medical_treatment ,medicine ,Stent ,Esophageal cancer ,medicine.disease ,business ,Prosthesis ,Surgery - Published
- 2002
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22. Comparison of plastic prostheses and self-expandable metallic stents in the treatment of malignant esophageal stenosis
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Makoto Takagi, Yoshiaki Osaka, Masato Moritani, Yasuhisa Koyanagi, Ryosuke Okada, Tatsuya Aoki, Shigeru Sato, Naoki Kuroda, Kazuhiko Tamura, and Yu Takagi
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Male ,medicine.medical_specialty ,Fistula ,medicine.medical_treatment ,Prosthesis ,Stomach Neoplasms ,Self-expandable metallic stent ,medicine ,Humans ,Ingestion ,Aged ,business.industry ,digestive, oral, and skin physiology ,Stent ,Prostheses and Implants ,Esophageal cancer ,medicine.disease ,Surgery ,Cardiac surgery ,Treatment Outcome ,Cardiothoracic surgery ,Esophageal Stenosis ,Female ,Stents ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Plastics ,Tracheoesophageal Fistula - Abstract
Objective: We compared the efficacy of plastic prostheses and self-expandable metallic stents in the treatment of malignant esophageal stenosis and/or fistula.Subjects and Methods: Subjects were 31 patients with esophageal cancer, 4 with esophagotracheal fistula, and 1 with esophageal stenosis. A plastic prosthesis was inserted in 15 patients (group A) and a self-expandable metallic stent in 21 patients (group B). We evaluated food ingestion improvement, effectiveness, complications, mean survival, food ingestion duration, the percentage of food ingestion capability in total survival time, and inhospital mortality.Results: No differences were seen in food intake improvement or in the effectiveness between groups, whereas fatal complications were higher in Group A. No significant differences were seen in mean survival, food ingestion duration, percentage of food ingestion capability, or inhospital mortality between groups.Conclusion: We concluded that a self-expandable metallic stent was safer than a plastic prosthesis because of fewer serious complications such as bleeding, and recommended the use of metallic stents in the treatment of malignant esophageal stenosis and/or fistula.
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- 2001
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23. Cross-sectional TEM study and film thickness dependence of Tc in heavily boron-doped superconducting diamond
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Ryosuke Okada, S. Kitagoh, Akihiro Kawano, Hiroshi Kawarada, M. Watanabe, Takahide Yamaguchi, Yoshihiko Takano, and T. Chikyow
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Materials science ,business.industry ,Energy Engineering and Power Technology ,Diamond ,Substrate (electronics) ,Crystal structure ,engineering.material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Carbon film ,Transmission electron microscopy ,engineering ,Optoelectronics ,Electrical and Electronic Engineering ,Thin film ,Dislocation ,business ,Layer (electronics) - Abstract
The film thickness dependence of Tc in heavily B-doped diamond (1 1 1) and (0 0 1) films was investigated and cross-sectional transmission electron microscope observation was employed to investigate the crystalline structure of heavily B-doped diamond. (1 1 1) films with 5 nm or more and (0 0 1) films with 40 nm or more show superconducting transition. Few dislocations are observed in 500 nm from the interface between the substrate and B-doped homoepitaxial layer in (1 1 1) film and defective structure observed in (0 0 1) film.
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- 2010
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24. Strategy for the Treatment of Carcinomata in the Advanced Aged Patients. Therapeutic Strategies for Esophageal Carcinoma in Elderly People
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Yasuhisa Koyanagi, Yosiaki Osaka, Shigeru Sato, Motoo Shinohara, Sumito Hoshino, Kazuhiko Tamura, Ryosuke Okada, Mikiya Hayashi, Kazutaka Okubo, Makoto Takagi, Yu Takagi, and Naoki Kuroda
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medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,medicine.disease ,Aged patients ,Surgery ,Esophagectomy ,Laparotomy ,medicine ,Carcinoma ,Elderly people ,Respiratory function ,Thoracotomy ,business ,Survival rate - Abstract
We encountered 588 patients with esophageal carcinoma between 1986 and 1998. For 96 (16.4%) of the patients 75-year-old or older, we examined the features and issues of esophageal carcinoma in elderly people based on preoperative conditions and treatment results. 1) Cardiac dysfunction was observed in 39 patients (40.6%). Concerning respiratory function, there was a significant difference in forced expiratory volume in 1 second (FEV1.0%) and % vital capacity (%VC) compared to patients under 75 years of ages (t-test). Furthermore, disorders of several organs were observed in 31 patients (32.2%). 2) Eleven patients underwent right thoracotomy and laparotomy. Three (25%) of these patients died in hospital postoperatively. The 3-year survival rate was 27.3%. 3) Fourteen patients underwent esophagectomy. Four (28.6%) of these patients died in hospital. The 3-year survival rate was 7.7%. 4) In 66 patients who did not undergo resection, the 3-year survival rate was 11.7%. 5) With respect to postoperative complications, the incidences of pulmonary complications and postoperative delirium were high. Some patients died during surgery or during hospitalization. Careful perioperative management is important. 6) There was no significant difference in long-term results between treatment methods. However, none of the patients who underwent C0 surgery survived more than 2 years. Therefore, this procedure should be avoided if possible.
- Published
- 2000
- Full Text
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25. A Case of Esophagobronchial Fistula Effectively Treated with Cyanoacrylate
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Naoki Kuroda, Ryosuke Okada, Aoki T, Mikiya Hayasi, Yasuhisa Koyanagi, Kazuhiko Tamura, Yosiaki Osaka, Yu Takagi, Makoto Takagi, and Sigeru Sato
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medicine.medical_specialty ,Cyanoacrylate ,law ,business.industry ,Gastroenterology ,medicine ,Surgery ,business ,Esophagobronchial Fistula ,law.invention - Abstract
従来より食道気管支瘻に対して, 保存的治療, 内視鏡治療, 手術などが行われてきた. 今回, 我々は生体接着剤であるEthyl-2-cyanoacrylate (以下, ECAと略す) を用いた内視鏡的瘻孔閉鎖術を試み, 良好な結果を得たので報告する.症例は73歳の男性. 平成9年6月初めより胸部不快感出現し, 6月6日内視鏡検査にて上切歯列より32cm, 3時方向に憩室があり, 憩室内に2mmの瘻孔を認めた. 7月2日瘻孔造影にて右B6から造影剤の流出を認めた. 7月10日散布チューブよりECA 1mlを瘻孔開口部に散布し, 造影にて瘻孔が閉鎖しているのを確認した. 散布後4日目の造影で一部造影剤の流出を認めたため, 再度ECA 1mlを散布した. 翌日より食事を開始し退院となった. ECAによる内視鏡的瘻孔閉鎖術は, 比較的簡単な手技で安全に繰り返し施行できるため, 手術を考慮する前や, 全身状態の悪い症例に有効な方法と思われた.
- Published
- 1999
- Full Text
- View/download PDF
26. Technical approach to individualized respiratory-gated carbon-ion therapy for mobile organs
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Takeshi Ebara, Satoshi Abe, Ken Yusa, Satoru Yamada, Ryosuke Okada, Mutsumi Tashiro, Tatsuya Ohno, Takashi Nakano, Hidemasa Kawamura, Tatsuaki Kanai, Takayoshi Ishii, Yoshiaki Ohashi, Keisuke Arai, Hirofumi Shimada, Yuji Kurosawa, and Jun-ichi Koya
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Organs at Risk ,medicine.medical_specialty ,Lung Neoplasms ,medicine.medical_treatment ,Errors ,Planning target volume ,Physical Therapy, Sports Therapy and Rehabilitation ,Heavy Ion Radiotherapy ,Dose distribution ,Patient Positioning ,Article ,Respiratory gating ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Four-Dimensional Computed Tomography ,Radiation treatment planning ,Radiation ,business.industry ,Phantoms, Imaging ,Smearing technique ,Radiotherapy Planning, Computer-Assisted ,Respiratory motion ,Radiotherapy Dosage ,General Medicine ,Carbon ,Radiation therapy ,4D CT ,Radiology Nuclear Medicine and imaging ,Carbon ion therapy ,Carbon-ion therapy ,Respiratory Mechanics ,Radiographic Image Interpretation, Computer-Assisted ,Radiology ,Nuclear medicine ,business ,Treatment planning - Abstract
We propose a strategy of individualized image acquisitions and treatment planning for respiratory-gated carbon-ion therapy. We implemented it in clinical treatments for diseases of mobile organs such as lung cancers at the Gunma University Heavy Ion Medical Center in June 2010. Gated computed tomography (CT) scans were used for treatment planning, and four-dimensional (4D) CT scans were used to evaluate motion errors within the gating window to help define the internal margins (IMs) and planning target volume for each patient. The smearing technique or internal gross tumor volume (IGTV = GTV + IM), where the stopping power ratio was replaced with the tumor value, was used for range compensation of moving targets. Dose distributions were obtained using the gated CT images for the treatment plans. The influence of respiratory motion on the dose distribution was verified with the planned beam settings using 4D CT images at some phases within the gating window before the adoption of the plan. A total of 14 lung cancer patients were treated in the first year. The planned margins with the proposed method were verified with clinical X-ray set-up images by deriving setup and internal motion errors. The planned margins were considered to be reasonable compared with the errors, except for large errors observed in some cases.
- Published
- 2012
27. Superconductor-to-insulator transition in boron-doped diamond films grown using chemical vapor deposition
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Akihiro Kawano, Yoshihiko Takano, Hitoshi Ishiwata, Ryosuke Okada, Takahide Yamaguchi, Shingo Iriyama, and Hiroshi Kawarada
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Superconductivity ,Boron doped diamond ,Materials science ,Doping ,Analytical chemistry ,chemistry.chemical_element ,Diamond ,Fermi surface ,Insulator (electricity) ,Chemical vapor deposition ,engineering.material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,chemistry ,engineering ,Boron - Abstract
The critical concentration of superconductor-to-insulator transition in boron-doped diamond is determined in two ways, namely, the actual doping concentration of boron and the Hall carrier concentration. Hall carrier concentrations in (111) and (001) films exceed the actual doping concentration owing to the distortion of the Fermi surface. The high critical boron concentration in (110) films is owing to the effect of the high concentration of interstitial boron atoms. A boron concentration of $3\ifmmode\times\else\texttimes\fi{}{10}^{20}\text{ }{\text{cm}}^{\ensuremath{-}3}$ in substitutional site is required for inducing superconductivity in diamond.
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- 2010
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28. [A case of gastric outlet obstruction by gallstone (Bouveret's syndrome) treated by EHL]
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Takayoshi, Yokoyama, Tatsuto, Ashizawa, Kouta, Hibi, Ryosuke, Okada, Yoshiaki, Suzuki, Makoto, Takagi, Yasushi, Shinohara, Katsutoshi, Sugimoto, and Tatsuya, Aoki
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Male ,Gastric Outlet Obstruction ,Lithotripsy ,Humans ,Gallstones ,Syndrome ,Middle Aged - Published
- 2005
29. Clinical significance of interleukin-6 (IL-6) in the spread of gastric cancer: role of IL-6 as a prognostic factor
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Toshiaki Aoki, Yoshiaki Suzuki, Makoto Takagi, Shinobu Ohnuma, Ryosuke Okada, Tatsuyuki Yamazaki, Tetsuo Sumi, Tatsuto Ashizawa, and Tatsuya Aoki
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Oncology ,Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Lymphovascular invasion ,Gastroenterology ,Stomach Neoplasms ,Internal medicine ,medicine ,Biomarkers, Tumor ,Humans ,Clinical significance ,Neoplasm Invasiveness ,Neoplasm Metastasis ,Interleukin 6 ,Lymph node ,Aged ,Aged, 80 and over ,biology ,business.industry ,Interleukin-6 ,Gene Expression Profiling ,Liver Neoplasms ,Cancer ,Interleukin ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,medicine.anatomical_structure ,Lymphatic Metastasis ,Cancer cell ,biology.protein ,Hepatocyte growth factor ,Female ,business ,Biomarkers ,medicine.drug - Abstract
Background. It is becoming clear that various cytokines are associated with the spread of cancer cells. The purpose of this study was to compare interleukin (IL)-6 levels in patients with gastric cancer to elucidate the role of IL-6 in predicting the spread of tumors. Methods. In 60 patients, we assessed the correlation of serum IL-6 (pg/ml) with stage, histological findings, hepatic metastasis, and related factors (hepatocyte growth factor [HGF], IL1� , tumor necrosis factor [TNF]-α, and transforming growth factor [TGF]-� 1). We also investigated the diagnostic significance of the IL-6 level for advanced gastric cancer and lymph node metastasis, as well as the association between IL-6 elevation and outcome. Finally, we examined the expression of IL-6 in tumor tissue. Results. Significant relationships were seen between serum IL-6 and stage, depth of tumor invasion (pT), lymphatic invasion (ly), venons invasion (v)*, lymph node metastasis (pN), hepatic metastasis (cH), and HGF (P 0.01; *P 0.05). With regard to the diagnostic significance of the IL-6 level for advanced gastric cancer and lymph node metastasis, when the cutoff value of IL-6 was set at 1.97 pg/ml, the sensitivity was 81.8% and 87.5%; specificity was 66.7% and 58.3%; and accuracy was 77.1% and 72.9%, respectively. The 1- and 3-year cumulative survival rates for patients with an IL-6 value of more than 1.97 pg/ml (69.0% and 43.4%, respectively) were significantly lower than those for patients with an IL-6 value of 1.97 pg/ml or less (94.4% and 87.2%, respectively; P 0.05). Immunohistochemical staining was positive for IL-6 in the cytoplasm of cancer cells. Conclusion. We suspect that IL-6 is involved in cancer invasion and lymph node and/or hepatic metastasis. Our results indicate that IL-6 could be used as a prognostic factor for survival.
- Published
- 2004
30. G071042 Autoignition characteristics of ethanol blended fuels
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Ryosuke Okada, Fumie Iwamura, Mitsuru Konno, and Kotaro Tanaka
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chemistry.chemical_compound ,Ethanol ,Chemical engineering ,Chemistry ,Autoignition temperature - Published
- 2013
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31. A case of anastomotic recurrence after surgery for gastric cancer with the fully worked-out stent placement
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Yoshiaki Osaka, Tatsuya Aoki, Shigeru Sato, Yu Takagi, Kazuhiko Tamura, Yasuhisa Koyanagi, Motoo Shinohara, and Ryosuke Okada
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medicine.medical_specialty ,Stent placement ,business.industry ,Mechanical Engineering ,General surgery ,medicine ,Energy Engineering and Power Technology ,Cancer ,Management Science and Operations Research ,Anastomosis ,medicine.disease ,business ,Surgery - Published
- 2001
- Full Text
- View/download PDF
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