74 results on '"K. Tateoka"'
Search Results
2. Performance evaluation of line scanning method in proton therapy
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Y. Azuma and K. Tateoka
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History ,Nuclear magnetic resonance ,Materials science ,Line scanning ,Proton therapy ,Computer Science Applications ,Education - Abstract
Proton therapy system (Sumitomo Heavy Industries, Ltd.) in Sapporo Teishinkai Hospital consists of a cyclotron, a rotating gantry and a multi-purpose nozzle. This nozzle can irradiate both wobbler beam and line scanning beam. Performance of line scanning was evaluated in this study. The authors investigated for items related to the beam delivery. Dose linearity was investigated with a water phantom and a large parallel plate chamber with several dose rates. For evaluation of irradiation time precision, a solid water phantom and the large parallel plate chamber were used. Furthermore, several spot patterns were measured by Scintillator/CCD camera system for the estimation of beam position. Dose linearity is found with less than 1.8 % error with varying conditions. Regarding irradiation time, error is also confirmed with less than about 1.4 % in this measurement. Beam position accuracy and beam size constancy is also precise enough to be used in clinical use. In conclusion, it is found that results in this study are good enough for treatment.
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- 2019
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3. EP-1384: The new method of the VMAT QA using Varian DynaLog Files and Modulation Complexity Score (MCS)
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M. Hareyama, K. Tateoka, and K. Fujimoto
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Oncology ,Modulation ,Computer science ,Radiology Nuclear Medicine and imaging ,Radiology, Nuclear Medicine and imaging ,Hematology ,Algorithm - Published
- 2015
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4. A novel GaAs power MESFET with low distortion characteristics employing semi-insulating setback layer under the gate
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K. Miyatsuji, Hidetoshi Furukawa, A. Sugimura, K. Tateoka, and Daisuke Ueda
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Materials science ,business.industry ,Electrical engineering ,Gain compression ,Electronic, Optical and Magnetic Materials ,Power (physics) ,Gallium arsenide ,chemistry.chemical_compound ,chemistry ,Modulation ,Adjacent channel ,Optoelectronics ,MESFET ,Electrical and Electronic Engineering ,Power MOSFET ,business ,Layer (electronics) - Abstract
A low distortion GaAs power MESFET has been developed by employing a semi-insulating setback layer under the gate. The setback region was obtained by diffusing chromium from the Cr/Pt/Au gate metal in self-aligned manner. The novel power FET with the setback layer was found to be insensitive to surface trapping effects. They showed only 5-6 percent frequency dispersion of drain current at 1 MHz compared to DC condition. Because of this small frequency dispersion, the typical measurement FET, which has a surface setback layer, with a gate width of 36 mm exhibited 1.5 dB larger output power at 1 dB gain compression point than that of the FET without the setback layer. Moreover, in the /spl pi//4 shift-QPSK modulation that has been most popular in digital mobile communication system, the FET exhibited 11 dB smaller adjacent channel leakage power than the conventional one at the output power of 31.5 dBm.
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- 1996
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5. A GaAs MCM power amplifier of 3.6 V operation with high efficiency of 49% for 0.9 GHz digital cellular phone systems
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A. Sugimura, H. Furukawa, K. Tateoka, N. Yoshikawa, and K. Kanazawa
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Radiation ,Materials science ,business.industry ,Amplifier ,Impedance matching ,Digital radio ,Condensed Matter Physics ,law.invention ,law ,Distortion ,Operational amplifier ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Low voltage ,Intermodulation ,Electronic circuit - Abstract
An extremely small GaAs PA (power amplifier) has been implemented using AlN multilayer MCM for 0.9 GHz digital cellular phones. The present PA exhibited high efficiency of 49% with drain supply voltage as low as 3.6 V. This PA was designed to provide matching circuits with the maximum gain at the input side and the minimum intermodulation distortion at the output side. Nonlinear simulation result verifies that this matching condition provides the lowest /spl pi//4-shift QPSK distortion and indicates that the phase shift of the amplifier is mainly caused by source-drain resistance. >
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- 1995
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6. Recovery Boiler Intelligent Control System
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K. Tateoka, W. Shinohara, N. Ozaki, and Hayashi Shinji
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Engineering ,Visual perception ,Artificial neural network ,business.industry ,Mechanical Engineering ,media_common.quotation_subject ,Control engineering ,General Chemistry ,Fuzzy control system ,Fuzzy logic ,Perception ,Media Technology ,Recovery boiler ,Intelligent control system ,General Materials Science ,business ,Intelligent control ,media_common - Abstract
The idea of applying intelligent control using neural networks and fuzzy logic to actual plants, where modern control theory is not powerful enough, is becoming popular. This paper presents one example applied to a recovery boiler in paper pulp mill.A recovery boiler aims to generate steam and to collect expensive soda, which is a waste from chemical reaction at the previous process. Experts still exist to operate the plant efficiently because of its process's complexity. Among them are the operators' actions based on the visual perception of the charbed. In order to reduce these operators' burden, control algorithm handling both conventional process data and image data is discussed in this paper.The control algorithm, visual feedback control, has two part. One is the perception of the charbed's shape organized by Neural Networks and the other is fuzzy control system based on operators' experience.First we discuss the present plant operations done by operators and point out the possibility of automatic manipulation. Next, explain the detailed algorithm including how we implemented neural networks and fuzzy logic. Finally the result of control to the plant is discussed.Due to the kindness support of a certain user, we have implemented this algorithm and evaluated to the actual plant.
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- 1993
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7. A high-power GaAlAs superluminescent diode with an antireflective window structure
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K. Hamada, Masahiro Kume, H. Naito, K. Tateoka, Masaaki Yuri, M. Kazumura, I. Teramoto, and H. Shimizu
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Materials science ,business.industry ,Condensed Matter Physics ,Superluminescent diode ,Atomic and Molecular Physics, and Optics ,Active layer ,Semiconductor laser theory ,law.invention ,Anti-reflective coating ,Optics ,law ,Optoelectronics ,Light beam ,Electrical and Electronic Engineering ,business ,Lasing threshold ,Beam (structure) ,Light-emitting diode - Abstract
A novel high-power GaAlAs superluminescent diode (SLD) structure that introduces an antireflective (AR) window region into the rear side of the SLD is proposed. The light beam which travels backward is emitted from the edge of the active layer and diverges in the window region. Then the beam is reflected at the AR-coated rear facet only by a small percentage, a fraction of which couples into the active layer. Thus, this window structure gives a reduction of the reflectivity at the interface between the active layer and the window region so that lasing oscillation is successfully suppressed. An SLD operation of output power as high as 50 mW is obtained with a stable fundamental spatial mode. The spectral bandwidth at half maximum is about 15 nm over a wide output power range. >
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- 1991
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8. A miniaturized GaAs power amplifier for 1.5 GHz digital cellular phones
- Author
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N. Yoshikawa, H. Furukawa, K. Kanazawa, S. Makioka, K. Tateoka, and S. Enomoto
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Engineering ,business.industry ,Amplifier ,Electrical engineering ,Mixed-signal integrated circuit ,Digital radio ,Integrated circuit ,Integrated circuit design ,law.invention ,law ,business ,Monolithic microwave integrated circuit ,Microwave ,Voltage - Abstract
An extremely miniaturized GaAs PA has been developed for the application in 1.5-GHz Japanese digital cellular phones. By using MuMIC (i.e. multilayer microwave integrated circuit) technology, the half sized (0.2 cc) PA with 1.1 W output power has successfully been implemented. The 48-% power-added efficiency has been obtained with drain supply voltage of 3.5-V.
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- 2002
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9. A high efficiency GaAs MCM power amplifier for 1.9 GHz digital cordless telephones
- Author
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M. Yuri, S. Makioka, K. Tateoka, K. Kanazawa, and N. Yoshikawa
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Materials science ,Cordless ,business.industry ,Amplifier ,Chip ,law.invention ,Capacitor ,Ultra high frequency ,law ,Optoelectronics ,business ,Low voltage ,Monolithic microwave integrated circuit ,Voltage - Abstract
A GaAs MCM power amplifier has been developed for 1.9-GHz digital cordless telephones. Power-added efficiency of 40.2% and P/sub 1dB/ of 22.2 dBm have been obtained at drain supply voltage of 3.6 V. Adoption of the MCM structure and on-chip ferroelectric capacitors has successfully reduced the GaAs total chip area to be 1.1 mm/sup 2/. >
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- 2002
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10. A GaAs MCM power amplifier of 3.6 V operation with high efficiency of 49% for 0.9 GHz digital cellular phone systems
- Author
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K. Tateoka, H. Furukawa, M. Yuri, A. Sugimura, K. Kanazawa, and N. Yoshikawa
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Power-added efficiency ,Engineering ,business.industry ,Cellular radio ,Amplifier ,Electrical engineering ,Hardware_PERFORMANCEANDRELIABILITY ,Gallium arsenide ,chemistry.chemical_compound ,chemistry ,Maximum gain ,Hardware_INTEGRATEDCIRCUITS ,business ,Voltage ,Electronic circuit ,Intermodulation - Abstract
Extremely small GaAs PA has been implemented using the AlN multilayer MCM for 0.9 GHz digital cellular phones. The present PA exhibited the efficiency of 49% with drain supply voltage as low as 3.6 V. The PA was designed to provide the matching circuits with the maximum gain at the input and the minimum intermodulation distortion at the output. >
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- 2002
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11. Temperature compensation technique of GaAs FET by rotating the gate orientation
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H. Furukawa, K. Tateoka, Tsuyoshi Tanaka, S. Nagata, T. Fukui, and Daisuke Ueda
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Materials science ,FET amplifier ,Thermal runaway ,business.industry ,Amplifier ,Gallium arsenide ,Compensation (engineering) ,Threshold voltage ,chemistry.chemical_compound ,chemistry ,Optoelectronics ,Rectangular potential barrier ,Power MOSFET ,business - Abstract
It is well known that GaAs power FET occasionally shows thermal runaway. There are some explanations about this effect, such as increase of leakage current and lowering the potential barrier of the gate as the increase of temperature. We found such effect is closely related to the gate orientation for the first time. Based on this characteristics of GaAs FET, we demonstrate temperature compensation technique of GaAs power amplifier just by rotating the gate orientation of the FET.
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- 2002
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12. Multilayer microwave integrated circuit technology for GaAs power amplifier of personal communication systems
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N. Toshikawa, S. Makioka, K. Tateoka, K. Miyatsuji, and K. Kanazawa
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Engineering ,business.industry ,Amplifier ,Impedance matching ,Electrical engineering ,Digital Enhanced Cordless Telecommunications ,Integrated circuit ,Die (integrated circuit) ,law.invention ,law ,business ,Monolithic microwave integrated circuit ,Microwave ,Electronic circuit - Abstract
Multilayer microwave integrated circuit, MuMIC, technology is realized by multilayer substrate of low cofired temperature ceramics. MuMIC multi-chip module (MCM) results in low cost, small size, and many functions for microwave applications. This technology is used for 1.9 GHz digital European cordless telecommunication (DECT) power amplifier. The GaAs MMIC die of the the MuMlC can be less than 1/10 compared to the conventional one by integrating the impedance matching circuits and filters in the layered structure reducing manufacturing cost. The outline of the MuMIC also is smaller than that of the conventional MMIC package. High power-added efficiency of the microwave power amplifier is obtained by taking advantage of the low resistance inner layer line ofthe MuMIC and the low on-resistance FETs.
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- 2002
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13. 1.5 V-operation GaAs spike-gate power FET with 65% power-added efficiency
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Takeshi Fukui, Hiroshi Takenaka, Atsushi Noma, Hidetoshi Furukawa, Tsuyoshi Tanaka, Daisuke Ueda, Tetsuzo Ueda, and K. Tateoka
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Power-added efficiency ,Materials science ,business.industry ,Transconductance ,Electrical engineering ,Power (physics) ,Gallium arsenide ,chemistry.chemical_compound ,chemistry ,Optoelectronics ,Output impedance ,Power MOSFET ,business ,Lithography ,Low voltage - Abstract
A GaAs power FET with a spike-gate has been developed for the high efficiency operation under the extremely low voltage supply of 1.5 V. The spike-gate provides both the low on-resistance of 2.2 /spl Omega//mm and the high transconductance of 180 mS/mm without reducing the output impedance nor increasing the gate resistance. The implemented device achieved the output power of 31.5 dBm with 65% power-added efficiency at the frequency of 900 MHz. Sub-quarter micron footprints of the spike-gate were defined by using the phase shift lithography.
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- 2002
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14. A GaAs single balanced mixer MMIC with built-in active balun for personal communication systems
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K. Tateoka, K. Kanazawa, D. Ueda, H. Koizumi, and S. Nagata
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Engineering ,business.industry ,Electrical engineering ,Impedance matching ,dBc ,Signal ,law.invention ,Capacitor ,law ,Filter (video) ,Balun ,Integrated circuit packaging ,business ,Monolithic microwave integrated circuit - Abstract
A GaAs single balanced mixer IC with built-in active baluns for IF and LO inputs has been developed. The present mixer achieved the conversion gain of 16 dB and the LO signal suppression over 30 dBc at the LO input power of 0 dBm. Owing to a novel BST (Barium Strontium Titanate) capacitor technology, the implemented mixer IC was packaged in the small 6 pin outline with the extremely small chip size of 0.6/spl times/0.65 mm/sup 2/. The IC can eliminate the LO filter of the up-conversion system for a variety of handyphone-sets in L-band. >
- Published
- 2002
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15. [Hormone therapy of endometrial carcinoma]
- Author
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H, Kuramoto, T, Jobo, Y, Kato, K, Tateoka, and R, Sato
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Tamoxifen ,Neoplasms, Hormone-Dependent ,Antineoplastic Agents, Hormonal ,Estrogen Antagonists ,Humans ,Female ,Progestins ,Endometrial Neoplasms - Abstract
Various hormone therapies for endometrial carcinoma have been reported in the literature using progestins, tamoxifen (anti-estrogen), danazol, Gn-RH etc. The response rates of these hormone therapies are reported to be approximately 30%, which is no longer superior to other types of treatment methods. On the other hand, endometrial carcinoma is considered to be one of hormone dependent tumors. Although sex steroid hormones play an important role in the mechanism of carcinogenesis and the progression of early and well-differentiated endometrial carcinoma, most of the advanced carcinomas treated by hormone therapy have transformed into hormone independent state. It is expected that endometrial hyperplasia and well-differentiated carcinoma especially in younger patients should be effective materials for hormone therapy.
- Published
- 1996
16. [Usefulness of continuous subcutaneous infusion of G-CSF for neutropenia due to chemotherapy for cancer]
- Author
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K, Tateoka, H, Hata, Y, Togasaki, T, Jobo, and H, Kuramoto
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Neutropenia ,Genital Neoplasms, Female ,Injections, Subcutaneous ,Granulocyte Colony-Stimulating Factor ,Humans ,Antineoplastic Agents ,Female ,Infusion Pumps - Published
- 1995
17. SU-E-T-267: A Comprehensive QA Method of MLC Accuracies for Dynamic IMRT
- Author
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K Tateoka, H Aoyama, M Yamada, Masataka Oita, and Motoharu Sasaki
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medicine.medical_specialty ,Computer science ,Random error ,medicine ,Medical physics ,General Medicine ,Irradiation ,Intensity-modulated radiation therapy ,Gantry angle - Abstract
Purpose: The purpose of this study was to investigate the usefulness of our original quality assurance (QA) program and patients' treatment of MLCdata analysis for dynamic IMRT as routine practice. Method and Materials: As to the QA program, we have made three MLC sweep test patterns by changing MLC travel speed of 0.5, 1.0 and 2.0 cm/sec, respectively. All three fields were irradiated by three gantry angles of 0, 90 and 270 degree as daily QA. Each MLC logs of the QA program and patients' treatment were recorded during Aug 2009 to Nov 2010. Actual MLC position errors (Bank A, Bank B) and gap errors compared with planned position were analyzed by a program (Matlab, Cybernet Inc.). Systematic and random errors of each MLC and gap were determined by everyday and every month. And then, the temporal data were also evaluated. Results: The accuracy of MLC position was depended upon its travel speed and gantry angle. Our data showed that the MLC errors in the QA program got worse as twice if the gantry angle was 270 deg compared to other angles. From patients' treatmentdata analysis, we could monitor the accuracy of MLC during the whole treatment courses. Conclusion: In this study, we have found that our original QA program and patients' treatment of MLCdata analysis could be useful for clinical routine MLC QA for dynamic IMRT to identify MLC position accuracies by time‐line.
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- 2011
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18. SU-E-T-395: Feasibility Study of a Novel Technique to Measure Instantly the Strength of 125I Seeds Being Implanted
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M Hareyama, Kenichi Tanaka, Jun Takada, M Hori, Hiromitsu Takeda, K Tateoka, Satoru Endo, Kaori Sato, K Kamo, and O Asanuma
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Novel technique ,Stable system ,Materials science ,Optics ,business.industry ,Detector ,General Medicine ,125i seed ,business ,Measure (mathematics) ,Counting rate - Abstract
Purpose: Final goal is to develop a technique to detect the 125I seed and measure its strength during implantation process. This will be a backup tool for QA by offering an additional measurement apart from the pre‐operation measurement. In actual implantation, the speed of the seed varies because it is conducted manually. In order to develop a simple and stable system usable in any speed, this study supposes to use single detector and repeat short‐time measurements. This report summarizes a feasibility test. Methods: The 125I seeds (Oncra Inc. Oncoseed 6711) was moved in speeds up to 200 mm/s by an electric actuator. Its strength was measured with a NaI detector (1″diam. × 1″) set at 170 mm from the needle guiding the seed. The requirement for the counting time was investigated to estimate the strength regardless the seed speed. Results: In the measurement where the seed was set static in needle, the change in counting rate of the NaI detector was 4 % at the 30 mm‐long region along the needle, while the counting rate rapidly decreased outside the region. It is desirable to start‐stop the measurement while the seed is within this region. Assuming 200 mm/s as the maximum speed, 7 to 8 measurements can be performed for the counting time of 20 ms, 3 measurements at 50 ms, 1 measurement at 100 ms. By using the average of the measured results while the seed was within the region, the estimated seed strength agreed within 10 % between the speeds 0 and 200 mm/s at counting time of 100 ms or less. Conclusion: This report shows the feasibility in principle to estimate the 125I seed strength during the implantation operation, regardless the seed velocity.
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- 2011
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19. 1467 poster AN ANALYSIS OF THE LONG TERM PRECISION OF MLC IN DYNAMIC IMRT THROUGH DAILY ROUTINE MLC QA
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K. Matsuda, S. Takahashi, K. Tateoka, S. Kuroda, K. Iwasaki, N. Uchida, M. Yamada, K. Kai, and O. Kunio
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medicine.medical_specialty ,Oncology ,business.industry ,medicine ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Hematology ,business ,Daily routine ,Term (time) - Published
- 2011
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20. A high-power GaAlAs superluminescent diode with an anti-reflective window structure
- Author
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Ken Hamada, Iwao Teramoto, H. Naito, K. Tateoka, Masahiro Kume, Masaaki Yuri, H. Shimizu, and M. Kazumura
- Subjects
Optical amplifier ,Optical fiber ,Materials science ,business.industry ,Window (computing) ,Optical modulation amplitude ,Superluminescent diode ,Waveguide (optics) ,law.invention ,Optics ,law ,Optoelectronics ,Stimulated emission ,Photonics ,business - Published
- 1990
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21. A04-6 Useful provocation test for the patients with alcohol related syncope
- Author
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K TATEOKA
- Subjects
Physiology (medical) ,Cardiology and Cardiovascular Medicine - Published
- 2003
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22. Theoretical consideration of the Dynamic jaw
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K. Tateoka, N. Saitou, and T. Saikawa
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General Medicine - Published
- 1996
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23. Construction of CT treatment planning system and image verification System
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T. Saikawa, K. Tateoka, and N. Saitou
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business.industry ,Computer science ,Verification system ,Computer vision ,General Medicine ,Artificial intelligence ,business ,Radiation treatment planning ,Image (mathematics) - Published
- 1995
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24. Evaluation of small field dosimetry
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T. Saikawa, N. Saitou, and K. Tateoka
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Physics ,Nuclear engineering ,Dosimetry ,General Medicine ,Small field - Published
- 1995
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25. Optical feedback in offset-structure optoelectronic integrated devices
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A. Sasaki, H. Sawatari, M. Itoh, Y. Takeda, T. Sakamoto, and K. Tateoka
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Distributed feedback laser ,Offset (computer science) ,Materials science ,business.industry ,Physics::Optics ,Heterojunction ,Integrated circuit ,Optical switch ,Atomic and Molecular Physics, and Optics ,law.invention ,Optical bistability ,Optics ,law ,Electrode ,Optoelectronics ,business ,Light-emitting diode - Abstract
An optical feedback mechanism in offset-structure integrated optoelectronic devices which exhibit light amplification, optical bistability, and regenerated oscillation is discussed. The amount of optical feedback was evaluated by adding a third electrode which allowed each of the integrated devices to be operated separately. Optical feedback control by an additional layer for the absorption of feedback light was demonstrated. >
- Published
- 1989
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26. A new composite‐cavity laser with two different waveguide cores for stable longitudinal mode operation
- Author
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Ken Hamada, K. Tateoka, H. Naito, H. Nagai, Hirokazu Shimizu, Masaaki Yuri, and M. Kume
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Materials science ,business.industry ,Physics::Optics ,General Physics and Astronomy ,Cladding (fiber optics) ,Laser ,law.invention ,Semiconductor laser theory ,Longitudinal mode ,Optics ,law ,Radiation mode ,Leaky mode ,business ,Lasing threshold ,Waveguide - Abstract
We have developed a new composite‐cavity laser with two different waveguide cores connected near the front mirror in the same cladding. This composite cavity has a built‐in structure that is capable of giving high mode selectivity because of strongly modulated reflectivity of the front mirror. The laser shows very stable single longitudinal mode operation in a temperature range as wide as about 50 °C for output powers from 3 to 100 mW without mode hopping.
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- 1989
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27. Continuous room‐temperature operation of a 759‐nm GaAlAs distributed feedback laser
- Author
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Shinichi Takigawa, H. Shimizu, H. Naitoh, A. Yamamoto, Kunio Itoh, K. Hamada, K. Tateoka, N. Yoshikawa, and Masahiro Kume
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Distributed feedback laser ,Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Chemical vapor deposition ,Semiconductor device ,Epitaxy ,Laser ,Semiconductor laser theory ,law.invention ,Wavelength ,law ,Continuous wave ,Optoelectronics ,business - Abstract
The first continuous wave (cw) operation at room temperature of a GaAlAs short‐wavelength distributed feedback (DFB) laser is reported. The cw operation at a wavelength of 759 nm was realized by use of the buried twin‐ridge substrate (BTRS) structure which has an excellent current confinement efficiency in the active region. The hybrid liquid phase epitaxy and the metalorganic chemical vapor deposition growth technology were used for the fabrication of short‐wavelength GaAlAs DFB BTRS lasers.
- Published
- 1987
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28. EP-1537: A study of accuracy evaluation of dose distribution calculation based on the cone-beam CT
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M. Hareyama, K. Fujimoto, and K. Tateoka
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Physics ,Oncology ,business.industry ,Radiology Nuclear Medicine and imaging ,Radiology, Nuclear Medicine and imaging ,Dose distribution ,Hematology ,Nuclear medicine ,business ,Cone beam ct - Full Text
- View/download PDF
29. Association between comorbidities associated with diabetes and higher-level functional status in older patients with type 2 diabetes mellitus: a cross sectional study.
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Shoji T, Kogure K, Toda N, Hakoshima M, Katsuyama H, Yanai H, Tokunaga S, Tateoka K, Tsuji T, and Okura T
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- Humans, Male, Aged, Female, Cross-Sectional Studies, Aged, 80 and over, Depression epidemiology, Frailty epidemiology, Cognitive Dysfunction epidemiology, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 complications, Comorbidity, Activities of Daily Living, Functional Status, Geriatric Assessment
- Abstract
Purpose: To investigate the association between comorbidities associated with diabetes and higher-level functional status as well as the relationship between comorbidities associated with diabetes and higher-level functional status in older patients with type 2 diabetes mellitus who have better social networks., Methods: Participants were outpatients with type 2 diabetes aged ≥ 65 years, excluding individuals with severe cardiovascular or respiratory illness, hyperglycaemic crisis, type 1 diabetes, or diabetic foot. The Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) was used to evaluate the higher-level functional status. A TMIG-IC score of ≤ 9, instrumental activities of daily living (IADL) ≤ 4, intellectual activity or social role ≤ 3 were defined as decline in higher-level functional status. The comorbidities investigated included peripheral neuropathy, retinopathy, nephropathy, cognitive impairment, depression, frailty, sarcopenia, low muscle strength, stroke, heart disease, and arthritis., Results: The analysis included 198 patients (mean age 75.9 ± 5.7 years, male 60.1%). After adjusting for potential confounders, depression was associated with TMIG-IC (Prevalence ratio (PR) 2.34, 95% confidence interval (CI) 1.44-3.82), low muscle strength was associated with IADL (PR 2.85, 95% CI 1.30-6.27), and frailty was associated with intellectual activity (PR 1.38, 95% CI 1.10-1.74). In the model with social networks added as a confounder, the relationship between depression or low muscle strength and higher-level functional status was not statistically significant., Conclusion: Comorbidities of depression and low muscle strength for older patients with type 2 diabetes mellitus increase the risk of malfunctioning of higher-level functional status. Increased interactions with family, friends and neighbours may reduce this event., (© 2024. The Author(s).)
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- 2024
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30. The relationship between acceleration in sit-to-stand and falls in community-dwelling older adults: cross-sectional study.
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Tateoka K, Tsuji T, Shoji T, Tokunaga S, and Okura T
- Abstract
[Purpose] This study aimed to determine the relationship between acceleration parameters in the sit-to-stand (STS) movement and falls, and the strength of the association between acceleration in STS movements and falls in older adults. [Participants and Methods] In total, 330 older adults were included. Four acceleration parameters were measured in STS movement: maximum acceleration (MA), velocity (MV), power (MP), and stand-up time (ST). For the conventional STS tests, 5 times STS test (5xSTS) and ground reaction force (maximal rate of force development per body weight: RFD/w, peak reaction force per body weight: F/w, chair-rise time: T) were measured. Poisson regression analysis adjusted for confounding factors was used. [Results] In the model adjusted for confounders, significant associations were observed among MV (Prevalence ratio (PR): 0.75; 95% confidence interval (CI): 0.58-0.98), MP (PR: 0.67; 95% Cl: 0.68-0.93), RFD/w (PR: 0.70; 95% Cl: 0.56-0.87), and T (PR: 1.14; 95% Cl: 1.05-1.24). [Conclusion] Among the acceleration parameters, MP was most strongly associated with falls and was considered the most useful parameter for evaluation. In addition, comparisons with the conventional chair rise tests suggested that MP was stronger than the 5xSTS test and may be equally related to the RFD/w., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results., (2024©by the Society of Physical Therapy Science. Published by IPEC Inc.)
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- 2024
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31. Dosimetric Comparison Study of Proton Therapy Using Line Scanning versus Passive Scattering and Volumetric Modulated Arc Therapy for Localized Prostate Cancer.
- Author
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Takagi M, Hasegawa Y, Tateoka K, Takada Y, and Hareyama M
- Abstract
Background: The proton irradiation modality has transitioned from passive scattering (PS) to pencil beam scanning. Nevertheless, the documented outcomes predominantly rely on PS., Methods: Thirty patients diagnosed with prostate cancer were selected to assess treatment planning across line scanning (LS), PS, and volumetric modulated arc therapy (VMAT). Dose constraints encompassed clinical target volume (CTV) D98 ≥ 73.0 Gy (RBE), rectal wall V65 < 17% and V40 < 35%, and bladder wall V65 < 25% and V40 < 50%. The CTV, rectal wall, and bladder wall dose volumes were calculated and evaluated using the Freidman test., Results: The LS technique adhered to all dose limitations. For the rectal and bladder walls, 10 (33.3%) and 21 (70.0%) patients in the PS method and 5 (16.7%) and 1 (3.3%) patients in VMAT, respectively, failed to meet the stipulated requirements. The wide ranges of the rectal and bladder wall volumes (V10-70) were lower with LS than with PS and VMAT. LS outperformed VMAT across all dose-volume rectal and bladder wall indices., Conclusion: The LS method demonstrated a reduction in rectal and bladder doses relative to PS and VMAT, thereby suggesting the potential for mitigating toxicities.
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- 2024
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32. [A longitudinal study of the association between physical activity and apathy among community-dwelling older adults].
- Author
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Tokunaga S, Tsuji T, Fujii K, Inoue T, Teraoka K, Tateoka K, Shoji T, and Okura T
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- Humans, Aged, Female, Male, Longitudinal Studies, Aged, 80 and over, Apathy, Exercise, Independent Living
- Abstract
Aim: This study clarified the association between the amount of physical activity and apathy after one year among community-dwelling older adults., Methods: Two hundred community-dwelling older adults (mean age: 74.3±5.0 years old, female: 52.5%) who participated in the 2018 and 2019 "Kasama Longevity Health Examination" were included. Apathy was assessed using the Apathy Scale (0-42 points; the higher the score, the lower the motivation), physical activity by Physical Activity Scale for the Elderly (PASE), and Geriatric Depression Scale-15 (GDS). The 2018 PASE data were grouped into tertiles. A multiple regression analysis was performed with the 2019 Apathy Scale as the dependent variable and the 2018 PASE as the independent variable, and the sex, age, years of education, economic situation, body mass index, chronic illness, smoking history, alcohol drinking habits, physical function, cognitive function, GDS, and the 2018 Apathy Scale as adjustment variables. The PASE subcategories (leisure-time, household, and work-related activities) were examined using a similar method., Results: The mean Apathy Scale in 2019 was 14.0±6.2 for the low physical activity group, 12.8±6.0 for the medium physical activity group, and 10.1±5.9 for the high physical activity group. The high physical activity group showed a significant negative association with the Apathy Scale (B=-1.56, 95% confidence interval=-2.91 to -0.21, p=0.023). No association was found for any activity of the PASE sub-items., Conclusions: A high level of physical activity may protect against apathy among community-dwelling older adults.
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- 2024
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33. Relationship between Acceleration in a Sit-To-Stand Movement and Physical Function in Older Adults.
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Tateoka K, Tsuji T, Shoji T, Tokunaga S, and Okura T
- Abstract
Acceleration parameters in sit-to-stand (STS) movements are useful for measuring lower-limb function in older adults. The purpose of this study was to examine the relationship between acceleration in STS movements and physical function and the test-retest reliability of acceleration parameters in older adults. We performed cross-sectional analyses on 244 older adults including 107 men (mean age: 77.4 ± 4.7) and 137 women (mean age: 75.6 ± 5.3). Four acceleration parameters were measured in STS movements: maximum acceleration (MA), maximum velocity (MV), maximum power (MP), and stand-up time (ST). Good intraclass correlation coefficients (ICC > 0.70) were observed for all parameters. For the acceleration parameters, MA, MV, and MP were relatively strongly associated with the 5-time STS test (men: r = -0.36~-0.47; women: r = -0.37~-0.45) and the timed up and go test (men: r = -0.39~0.47, women: r = -0.43~-0.51): MP was also strongly associated with grip strength (men: r = 0.48, women: r = 0.43). All acceleration parameters were poorer in participants reporting mobility limitations than in those reporting no mobility limitations. These findings support the usefulness of sensor-based STS measurement. The system is expected to be useful in various settings where care prevention is addressed.
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- 2023
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34. Cross-sectional and longitudinal study of the relationship between phase angle and physical function in older adults.
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Asano Y, Tsuji T, Kim M, Nagata K, Shibuya K, Tateoka K, and Okura T
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- Male, Humans, Female, Aged, Longitudinal Studies, Time and Motion Studies, Walking physiology, Postural Balance physiology, Independent Living
- Abstract
Aim: Although the validity of the assessment in older adults has been supported by several studies, cross-sectional and longitudinal relationships between phase angle (PhA) and physical function by sex have not been clarified. This study aimed to examine (i) cross-sectional relationships and (ii) longitudinal relationships between PhA and physical function in older adults., Methods: A total of 816 and 445 community-dwelling older adults were included in cross-sectional and longitudinal analyses, respectively. We evaluated their physical function using grip strength, 5-repetition sit-to-stand test (5-STS), 5-meter habitual walk, Timed Up and Go test (TUG), single-leg balance with eyes open, and sit-and-reach test. A multifrequency bioelectrical impedance analyzer was used to determine the PhA at 50 kHz as well as the participants' body composition., Results: In the cross-sectional analysis, a higher PhA was significantly associated with higher grip strength, sit-and-reach, single-leg balance with eyes open, 5-STS and lower TUG in women, as well as higher grip strength, single-leg balance with eyes open, lower 5-STS and TUG in men, adjusting for age, body mass index and muscle mass. In the longitudinal analysis, there was a significant interaction between PhA and year in the TUG test (B = -0.08; 95% CI, -0.136 to -0.025; P = 0.005) in men. There was no significant interaction between the PhA value and year for the other physical functions., Conclusions: The PhA is a useful indicator for assessing physical function in both older men and women. Furthermore, the PhA may be able to predict mobility limitation in older men. Geriatr Gerontol Int 2023; 23: 141-147., (© 2023 Japan Geriatrics Society.)
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- 2023
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35. Evaluation of Cognitive and Physical Function Among Older Adults by Their Physical Activity: A Cross-Sectional Kasama Study, Japan.
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Yoon J, Sasaki K, Tateoka K, Arai T, Isoda H, and Okura T
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- Humans, Aged, Aged, 80 and over, Cross-Sectional Studies, Japan, Cognition, Exercise, Amyloid beta-Peptides, Cognitive Dysfunction diagnosis, Cognitive Dysfunction psychology, Alzheimer Disease
- Abstract
Background: The amyloid-β1-42 (Aβ42) level is a biomarker that is widely used to evaluate individual cognitive dysfunction early in neurodegenerative diseases, as well as differentiate between normal cognitive function, mild cognitive impairment, Alzheimer's disease, and vascular cognitive impairment., Objective: Our cross-sectional study evaluated the association between daily exercise and physical and cognitive function and Aβ42 levels among a subsample of 325 older adults from the Kasama Study., Methods: Participants (age: 74.5 [range 65-90] years) were classified into three exercise groups: the dual-task (DEG, n = 128), single-task (SEG, n = 122), and non-exercise (NEG, n = 75) groups. The main outcomes were the plasma Aβ42 levels and the scores of the five cognitive (5-COG) tests and five cognition-related physical function (5-PHYS) tests., Results: The Aβ42 levels and 5-COG and 5-PHYS scores were higher in the SEG and DEG than in the NEG. The Aβ42 levels were higher in the DEG than in the NEG (p = 0.008)., Conclusions: Physical activities such as regular exercise may benefit older adults, improving their cognitive and physical function.
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- 2023
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36. Frail Older Adults without Occupational Dysfunction Maintain Good Subjective Well-Being: A Cross-Sectional Study.
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Fujii K, Fujii Y, Kubo Y, Tateoka K, Liu J, Nagata K, Nakashima D, and Okura T
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The purpose of this cross-sectional study was to clarify the relationship between frailty/occupational dysfunction (OD), both with and without, and subjective well-being among community-dwelling older adults. A total of 2308 (average age: 72.2 ± 5.1, female: 47.0%) independently living older adults in Kasama City, Japan, completed a self-administered questionnaire in November 2019. OD, frailty, and subjective well-being were assessed. Participants were classified into six groups: robust and healthy occupational function (HOF), robust and OD, pre-frail and HOF, pre-frail and OD, frail and HOF, and frail and OD. To examine the relationship between frailty/OD and subjective well-being, we performed an analysis of variance with subjective well-being as the dependent variable and with and without frailty/OD (six groups) as the independent variables. The results showed a significant association between with and without frailty/OD and subjective well-being in community-dwelling older adults. The subjective well-being of the pre-frail and HOF group was significantly better than that of the robust and OD group. Furthermore, the subjective well-being of the frail and HOF group was significantly better than that of the pre-frail and OD group. These results can be used to develop a new support method for frailty.
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- 2022
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37. The association of the Japan Science and Technology Agency Index of Competence with physical and cognitive function in community-dwelling older adults.
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Shoji T, Fujii Y, Tateoka K, Tsuji T, and Okura T
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- Aged, Humans, Japan, Physical Examination, Technology, Cognition, Independent Living psychology
- Abstract
Aim: To investigate the association of the Japan Science and Technology Agency Index of Competence with physical and cognitive functions in community-dwelling older adults., Methods: This study used the data of 565 community-dwelling adults aged ≥65 years (mean age: 74.3 ± 5.2 years) from the Kasama Health Checkup for Longevity survey in Japan. The Japan Science and Technology Agency Index of Competence was used to comprehensively evaluate the higher-level functional capacity and subscale functional capacity: technology usage, information practice, life management and social engagement. Physical functions were assessed using grip strength, the five-repetition sit-to-stand test, 5-m habitual walking test, one-leg standing test and hand working test with a pegboard. Cognitive functions were evaluated using the Five-Cog test consisting of attention, memory ability, visuospatial function, language ability and reasoning ability. Multiple regression analysis was conducted to examine the associations between total Japan Science and Technology Agency Index of Competence score and physical and cognitive functions., Results: After adjusting for potential confounders, the total Japan Science and Technology Agency Index of Competence score was favorably associated with static balance ability (β = 0.09; B = 0.01; 95% confidence interval: 0.00-0.02), lower limb strength (β = -0.19; B = -0.29; 95% confidence interval: -0.41 to -0.16), walking ability (β = -0.15; B = -0.67; 95% confidence interval: -1.05 to -0.30), hand dexterity (β = -0.13; B = -0.08; 95% confidence interval: -0.14 to -0.03) and overall cognitive function (β = 0.28; B = 0.04; 95% confidence interval: 0.03-0.05)., Conclusions: Physical and cognitive functions are important for maintaining higher-level functional capacity. Geriatr Gerontol Int 2022; 22: 753-758., (© 2022 Japan Geriatrics Society.)
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- 2022
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38. [Relationship between performance on the Digital Trail Making Peg test and cognitive function in older adults].
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Inoue T, Nagata K, Tateoka K, Seol J, Yoon J, Tsuji T, and Okura T
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- Aged, Aged, 80 and over, Body Mass Index, Cognition, Humans, Independent Living, Cognition Disorders, Thymidine Monophosphate
- Abstract
Aim: To determine the relationship between performance on the Digital Trail Making Peg test (DTMP) and cognitive function in older adults., Methods: A total of 203 community-dwelling older adults (mean age: 76.4±5.1 years old) participated in this study. The five-cog test was used to assess the cognitive function. The DTMP measured completion time, number of errors and intra-individual variability for performance variability (coefficient of variation, CV; inter-elemental variability, IEV). Spearman's rank correlation coefficient (ρ) was calculated to examine the association between each variable. In addition, a multiple regression analysis was performed with the cognitive function score as the dependent variable and the DTMP completion time, number of errors, CV, and IEV as the independent variables, with adjusting for the sex, age, years of education, body mass index, medical history, depression, and physical function., Results: The rank correlation coefficients with cognitive function scores were as follows: completion time, ρ = -0.479 (P < 0.01), number of errors, ρ = -0.068 (P = 0.332), CV, ρ = 0.085 (P = 0.225), IEV, ρ = -0.316 (P < 0.01). The results of the multiple regression analysis showed that completion time (β = -0.566), CV (β = 0.164), IEV (β = 2.736) were significantly associated with cognitive function scores., Conclusions: The shorter the DTMP completion time, the better the overall cognitive function. However, the intra-individual variability of CV and IEV did not show consistent results, with smaller values indicating less intra-individual variability.
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- 2022
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39. Pre-frailty associated with traffic crashes in Japanese community-dwelling older drivers.
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Liu J, Fujii Y, Fujii K, Seol J, Kim M, Tateoka K, Nagata K, Zhang H, and Okura T
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- Accidents, Traffic, Aged, Cross-Sectional Studies, Humans, Independent Living, Japan epidemiology, Automobile Driving, Frailty epidemiology
- Abstract
Objectives: Frailty might be useful to identify older drivers who are at risk for traffic crashes. We aim to examine the association between pre-frailty/frailty defined by the Kihon Checklist (KCL) and the involvement of traffic crashes and clarify whether some domains of the KCL are associated with traffic crashes. Methods: This cross-sectional study analyzed data from 2,208 Japanese community-dwelling older drivers aged ≥ 65 years in Kasama City, who participated in our postal survey in November 2019. A self-reported history of traffic crashes was used to divide participants into non-crash-involved and crash-involved groups. Results: A total of 192 (8.7%) participants had been involved in traffic crashes in the past year. The crash-involved group was found to have gained more body mass index, driven more frequently, and scored higher on the total KCL score than the non-crash-involved group (all P < .05). Binary logistic regression analyses showed that after adjusting for age, sex, education, driving frequency, and driving distance, pre-frailty (OR = 1.52, 95% CI: 1.10-2.10) was more significantly associated with traffic crashes as compared to robustness. Those who had impairment in the oral domain (OR = 1.57, 95% CI: 1.09-2.27) and memory domain (OR = 1.38, 95% CI: 1.01-1.90) were also more likely to be involved in traffic crashes. Conclusion: The results suggest that identifying pre-frailty may play an important pole in crash prevention. Additionally, more attention should be given to older drivers with oral dysfunction and cognitive impairment.
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- 2022
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40. Combined effect of daily physical activity and social relationships on sleep disorder among older adults: cross-sectional and longitudinal study based on data from the Kasama study.
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Seol J, Lee J, Nagata K, Fujii Y, Joho K, Tateoka K, Inoue T, Liu J, and Okura T
- Subjects
- Aged, Cross-Sectional Studies, Humans, Interpersonal Relations, Longitudinal Studies, Sleep, Exercise, Sleep Wake Disorders diagnosis, Sleep Wake Disorders epidemiology
- Abstract
Background: This study investigated whether daily physical activity of older adults, combined with social relationships, is associated with the risk of sleep disorder. Further, it determined whether a high level of one variable with a low level of the other, leads to a significantly lower risk of sleep disorder than low levels of both., Methods: The sample comprised 1339 community-dwelling older Japanese adults: 988 in Study 1 and 351 in Study 2. The level of daily physical activity and range of social relationships were assessed using the Physical Activity Scale for the Elderly and the Lubben Social Network Scale, respectively. The Pittsburgh Sleep Quality Index was used to assess sleep disorder. To test the combined relationships and effects in Studies 1 and 2, the medians for the respective scores of each of the following four groups that the participants were categorized into, were calculated: (1) low activity group with low social relationships, (2) low activity group with high social relationships, (3) high activity group with low social relationships, and (4) high activity group with high social relationships. After adjusting for potential confounders, a logistic regression analysis was conducted in Study 1. After adjusting for potential confounders, a Cox proportional hazards regression analysis was conducted in Study 2., Results: Study 1 revealed that the high activity group with high social relationships showed a significantly lower risk of sleep disorder (ORs: 0.585, 95% CI: 0.404-0.847) than the low activity group with low social relationships. Study 2 also revealed that the high activity group with high social relationships showed a significantly lower prevalence of sleep disorder (HRs: 0.564, 95% CI: 0.327-0.974) than the low activity group with low social relationships., Conclusions: Our findings suggest that for older adults with high social relationships, being physically active is favorably associated with sleep quality. However, a high level of one variable with a low level of the other has not been confirmed in improving sleep quality among older adults., (© 2021. The Author(s).)
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- 2021
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41. Ultrasound-guided internal jugular venipuncture using pocket-sized versus standard ultrasound devices: a prospective non-inferiority trial.
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Yamamoto K, Inagaki Y, Iwata C, Tada M, Tateoka K, and Sasakawa T
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- Humans, Jugular Veins diagnostic imaging, Jugular Veins surgery, Prospective Studies, Ultrasonography, Interventional, Catheterization, Central Venous, Phlebotomy
- Abstract
Purpose: Pocket-sized ultrasound devices (PUDs) are commonly adopted for bedside use despite their inferior performance compared with standard ultrasound devices (SUDs). We investigated the non-inferiority of PUDs versus SUDs for ultrasound-guided internal jugular venipuncture., Methods: All patients undergoing scheduled surgery with general anesthesia and internal jugular vein catheter placement were prospectively included in this randomized non-inferiority trial to compare the qualities of the internal jugular venipuncture between the PUD group (Group P) and SUD group (Group S). The primary endpoint was puncture time, and the secondary endpoints included number of punctures, needle and guidewire visibility, and anatomic visibility., Results: Fifty-two patients were randomized to one of the two groups (26 per group). The mean (SEM) puncture time was 56.4 (10.9) s in Group P and 45.5 (4.0) s in Group S. The mean difference of 10.9 s was within the prespecified non-inferiority margin of 100% (two-sided 95% CI: - 12.9-34.6, upper limit of the 95% CI: 45.5) for puncture time. The mean (SEM) number of punctures was 1.15 (0.12) times in Group P and 1.12 (0.06) times in Group S. The difference of 0.04 punctures was within the prespecified non-inferiority margin of 100% (two-sided 95% CI: - 0.24-0.31, upper limit of the 95% CI: 1.12) for number of punctures. Non-inferiority was not shown for needle and guidewire visibility and anatomic visibility., Conclusion: PUDs for internal jugular venipuncture are not inferior to SUDs with regard to puncture time and number of punctures, despite differences in visibility and device performance., (© 2021. The Japan Society of Ultrasonics in Medicine.)
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- 2021
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42. Association between Occupational Dysfunction and Social Isolation in Japanese Older Adults: A Cross-Sectional Study.
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Fujii K, Fujii Y, Kubo Y, Tateoka K, Liu J, Nagata K, Wakayama S, and Okura T
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- Aged, Cross-Sectional Studies, Humans, Japan epidemiology, Surveys and Questionnaires, Independent Living, Social Isolation
- Abstract
We clarified the relationship between occupational dysfunction and social isolation among community-dwelling adults. We used a self-administered questionnaire with a cross-sectional study for 2879 independently living older adults in Kasama City, Japan. Participants responded to a self-reported questionnaire in November 2019. Occupational dysfunction and social isolation were assessed. The participants were classified into two groups: healthy occupational function group, and occupational dysfunction group. To examine the relationship between occupational dysfunction and social isolation, we performed a logistic regression analysis with social isolation as a dependent variable and occupational dysfunction as an independent variable. In the crude model, the occupational dysfunction group had a higher risk of social isolation than the healthy occupational function group (odds ratio (OR) = 2.04; 95% confidence interval (CI), 1.63-2.55; p < 0.001). In the adjusted model, the occupational dysfunction group had a higher risk of social isolation than the healthy occupational function group (OR = 1.51; 95% CI, 1.17-1.94; p = 0.001). The results showed that occupational dysfunction was significantly associated with social isolation. These results can be used in constructing a support method for social isolation from a new perspective.
- Published
- 2021
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43. Desflurane for management of decompressive laminectomy in a patient with hereditary spastic paraplegia: a case report.
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Tada M, Tateoka K, Yamamoto K, Inagaki Y, and Kunisawa T
- Abstract
Background: Hereditary spastic paraplegia (HSP) is a rare, genetic neurodegenerative condition. Thus far, ideal anesthetic management is not established for patients with HSP; therefore, careful selection and dosage of anesthetic agents is required., Case Presentation: A 54-year-old woman with HSP, who was diagnosed with severe lumbar spinal canal stenosis, underwent decompressive laminectomy to relieve her back pain. Preoperatively, she experienced slight difficulty in walking independently; however, she exhibited no other dysfunction. Anesthesia was maintained with desflurane after tracheal intubation. Rocuronium and sugammadex were used for neuromuscular blockade and reversal, respectively, with neuromuscular monitoring equipment. The patient showed uneventful postoperative recovery without signs of neurological deterioration after extubation., Conclusions: Our successful experience in this case implies that, for patients with neuromuscular diseases, including HSP, desflurane may be an option for anesthetic management; moreover, careful assessment (e.g., medical condition, bispectral index, and train-of-four) should be performed prior to administration of anesthesia.
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- 2019
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44. An in vitro verification of strength estimation for moving an 125I source during implantation in brachytherapy.
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Tanaka K, Kajimoto T, Hayashi T, Asanuma O, Hori M, Kamo KI, Sumida I, Takahashi Y, Tateoka K, Bengua G, Sakata KI, and Endo S
- Subjects
- Calibration, Humans, Brachytherapy, Iodine Radioisotopes chemistry
- Abstract
This study aims to demonstrate the feasibility of a method for estimating the strength of a moving brachytherapy source during implantation in a patient. Experiments were performed under the same conditions as in the actual treatment, except for one point that the source was not implanted into a patient. The brachytherapy source selected for this study was 125I with an air kerma strength of 0.332 U (μGym2h-1), and the detector used was a plastic scintillator with dimensions of 10 cm × 5 cm × 5 cm. A calibration factor to convert the counting rate of the detector to the source strength was measured and then the accuracy of the proposed method was investigated for a manually driven source. The accuracy was found to be under 10% when the shielding effect of additional needles for implantation at other positions was corrected, and about 30% when the shielding was not corrected. Even without shielding correction, the proposed method can detect dead/dropped source, implantation of a source with the wrong strength, and a mistake in the number of the sources implanted. Furthermore, when the correction was applied, the achieved accuracy came close to within 7% required to find the Oncoseed 6711 (125I seed with unintended strength among the commercially supplied values of 0.392, 0.462 and 0.533 U).
- Published
- 2018
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45. Influence of Ku86 and XRCC4 expression in uterine cervical cancer on the response to preoperative radiotherapy.
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Takada Y, Someya M, Matsumoto Y, Satoh M, Nakata K, Hori M, Saito M, Hirokawa N, Tateoka K, Teramoto M, Saito T, Hasegawa T, and Sakata KI
- Subjects
- Adult, Aged, Biopsy, Cell Count, DNA End-Joining Repair genetics, Disease-Free Survival, Female, Humans, Middle Aged, Neoplasm Metastasis, Neoplasm Staging, Treatment Outcome, Uterine Cervical Neoplasms pathology, DNA-Binding Proteins metabolism, Ku Autoantigen metabolism, Preoperative Care, Uterine Cervical Neoplasms metabolism, Uterine Cervical Neoplasms surgery
- Abstract
DNA double-strand breaks (DSB) are severe damages induced by ionizing radiation. Non-homologous end joining (NHEJ) is a major mechanism for repairing DSB. Immunohistochemical analysis of proteins involved in NHEJ, such as Ku86 and XRCC4 (X-ray repair cross-complementing protein 4) may be useful for predicting tumor radiosensitivity. We examined the relationship between expression of DSB-related proteins in biopsy specimens of uterine cervical cancer and the pathological effect of 40 Gy of preoperative radiotherapy. 119 patients with uterine cervical cancer were treated between 2000 and 2011. Pathological effects of preoperative radiotherapy were classified by examining hysterectomy specimens. Patients with complete response (pCR) had a significantly better overall 5-year survival rate than those without pCR (96.3 vs. 76.9 %, P = 0.02). The pCR rate was significantly higher in patients with low Ku86 and XRCC4 expression than in other patients (47.4 vs. 21.3 %, P = 0.04). Logistic regression analysis also demonstrated that low Ku86 and XRCC4 expression was a significant predictor of pCR (P = 0.03). Patients with high Ku86 and XRCC4 expression had a significantly lower 5-year metastasis-free rate than others (79.3 vs. 93.5 %, P = 0.02). Proteins involved with NHEJ might have an influence on results of radiotherapy for uterine cervical cancer.
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- 2016
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46. Analysis of Prostate Deformation during a Course of Radiation Therapy for Prostate Cancer.
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Nakazawa T, Tateoka K, Saito Y, Abe T, Yano M, Yaegashi Y, Narimatsu H, Fujimoto K, Nakata A, Nakata K, Someya M, Hori M, Hareyama M, and Sakata K
- Subjects
- Humans, Male, Organ Size, Prostate pathology, Prostatic Neoplasms diagnostic imaging, Prostate diagnostic imaging, Prostatic Neoplasms radiotherapy, Radiographic Image Interpretation, Computer-Assisted
- Abstract
Purpose: Accurate analysis of the correlation between deformation of the prostate and displacement of its center of gravity (CoG) is important for efficient radiation therapy for prostate cancer. In this study, we addressed this problem by introducing a new analysis approach., Method: A planning computed tomography (CT) scan and 7 repeat cone-beam CT scans during the course of treatment were obtained for 19 prostate cancer patients who underwent three-dimensional conformal radiation therapy. A single observer contoured the prostate gland only. To evaluate the local deformation of the prostate, it was divided into 12 manually defined segments. Prostate deformation was calculated using in-house developed software. The correlation between the displacement of the CoG and the local deformation of the prostate was evaluated using multiple regression analysis., Results: The mean value and standard deviation (SD) of the prostate deformation were 0.6 mm and 1.7 mm, respectively. For the majority of the patients, the local SD of the deformation was slightly lager in the superior and inferior segments. Multiple regression analysis revealed that the anterior-posterior displacement of the CoG of the prostate had a highly significant correlation with the deformations in the middle-anterior (p < 0.01) and middle-posterior (p < 0.01) segments of the prostate surface (R2 = 0.84). However, there was no significant correlation between the displacement of the CoG and the deformation of the prostate surface in other segments., Conclusion: Anterior-posterior displacement of the CoG of the prostate is highly correlated with deformation in its middle-anterior and posterior segments. In the radiation therapy for prostate cancer, it is necessary to optimize the internal margin for every position of the prostate measured using image-guided radiation therapy.
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- 2015
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47. Relation between Ku80 and microRNA-99a expression and late rectal bleeding after radiotherapy for prostate cancer.
- Author
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Someya M, Yamamoto H, Nojima M, Hori M, Tateoka K, Nakata K, Takagi M, Saito M, Hirokawa N, Tokino T, and Sakata K
- Subjects
- Aged, Gastrointestinal Hemorrhage etiology, Gene Expression Regulation, Humans, Ku Autoantigen, Male, Radiotherapy adverse effects, Antigens, Nuclear genetics, DNA-Binding Proteins genetics, Gastrointestinal Hemorrhage genetics, MicroRNAs genetics, Prostatic Neoplasms radiotherapy, Radiation Injuries genetics, Rectum injuries
- Abstract
Background and Purpose: Late rectal bleeding is one of the severe adverse events after radiotherapy for prostate cancer. New biomarkers are needed to allow a personalized treatment., Materials and Methods: Four patients each with grade 0-1 or grade 2-3 rectal bleeding were randomly selected for miRNA array to examine miRNA expression in peripheral blood lymphocytes (PBLs). Based on results of miRNA array, 1 of 348 miRNAs was selected for microRNA assays. Then, expression of DNA-dependent protein kinase mRNA and miR-99a was analyzed in the PBLs of 97 patients. PBLs were exposed to 4Gy of X-ray ex-vivo., Results: In the discovery cohort, grade 2-3 rectal bleeding was significantly higher in the Ku80 <1.09 expression group compared with ⩾1.09 group (P=0.011). In radiation-induced expression of miR-99a, grade 2-3 rectal bleeding was significantly higher in the miR-99a IR(+)/IR(-) >0.93 group compared with ⩽0.93 group (P=0.013). Most patients with grade 2-3 rectal bleeding were in the group with low Ku80 and high miR-99a expression. In the validation cohort, similar results were obtained., Conclusion: A combination of low Ku80 expression and highly-induced miR-99a expression could be a promising marker for predicting rectal bleeding after radiotherapy., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
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- 2015
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48. A comparison of the dose distributions between the brachytherapy 125I source models, STM1251 and Oncoseed 6711, in a geometry lacking radiation equilibrium scatter conditions.
- Author
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Tanaka K, Kamo K, Tateoka K, Asanuma O, Sato K, Takeda H, Sakata K, and Takada J
- Subjects
- Brachytherapy instrumentation, Computer Simulation, Humans, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted instrumentation, Reproducibility of Results, Scattering, Radiation, Sensitivity and Specificity, Software, Algorithms, Brachytherapy methods, Models, Biological, Radiotherapy Planning, Computer-Assisted methods
- Abstract
The purpose of this study was to estimate the uncertainty in the dose distribution for the (125)I source STM1251, as measured with a radiophotoluminescent glass rod dosimeter and calculated using the Monte Carlo code EGS5 in geometry that included the source structure reported by Kirov et al. This was performed at a range of positions in and on a water phantom 18 cm in diameter and 16 cm in length. Some dosimetry positions were so close to the surface that the backscatter margin was insufficient for photons. Consequently, the combined standard uncertainty (CSU) at the coverage factor k of 1 was 11.0-11.2% for the measurement and 1.8-3.6% for the calculation. The calculation successfully reproduced the measured dose distribution within 13%, with CSU at k ≤ 1.6 (P > 0.3). Dose distributions were then compared with those for the (125)I source Oncoseed 6711. Our results supported the American Association of Physicists in Medicine Task Group No. 43 Updated Protocol (TG43U1) formalism, in which STM1251 dose distributions were more penetrating than those of Oncoseed 6711. This trend was also observed in the region near the phantom surface lacking the equilibrium radiation scatter conditions. In this region, the difference between the TG43U1 formalism and the measurement and calculation performed in the present study was not significant (P > 0.3) for either of the source models. Selection of the source model based on the treatment plans according to the TG43U1 formalism will be practical., (© The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.)
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- 2015
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49. Affinity Selection of Peptide Binders with Magnetic Beads via Organic Phase Separation (MOPS).
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Murai R, Nogi T, Tateoka K, and Sato A
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- Animals, Antibodies, Monoclonal, Murine-Derived isolation & purification, Humans, Ligands, Magnets, Mice, Solutions, Antibodies, Monoclonal isolation & purification, Bacteriophages, Integrins immunology, Peptide Library, Peptides isolation & purification
- Abstract
We describe a new method for affinity selection of peptide binders for soluble protein targets using magnetic beads via organic phase separation (MOPS) from a phage display library. As a model target molecule, a mouse monoclonal antibody against human integrin α9β1 (Y9A2) immobilized onto protein G magnetic beads was incubated with a 15-mer or 20-mer random peptide phage-display library. The suspensions containing the phage-magnetic beads conjugates were then transferred onto the organic phase and centrifuged in order to recover the Y9A2 bound phage immobilized on the protein G magnetic beads in the lower organic phase. After three rounds of biopanning, we were able to isolate specific phage clones that could not be obtained by the conventional approach. Furthermore, this new approach was found to be highly effective for isolating phage-binders for Fc-fusion constructs; indeed, enrichment of specific phage-binders was observed after only the first panning cycle. Thus, MOPS can improve the selection of specific phage-binders for soluble protein targets mainly due to the removal of non-specific binders.
- Published
- 2015
- Full Text
- View/download PDF
50. Results and DVH analysis of late rectal bleeding in patients treated with 3D-CRT or IMRT for localized prostate cancer.
- Author
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Someya M, Hori M, Tateoka K, Nakata K, Takagi M, Saito M, Hirokawa N, Hareyama M, and Sakata K
- Subjects
- Aged, Aged, 80 and over, Causality, Comorbidity, Dose Fractionation, Radiation, Dose-Response Relationship, Radiation, Gastrointestinal Hemorrhage prevention & control, Humans, Japan, Longitudinal Studies, Male, Middle Aged, Prevalence, Radiation Protection statistics & numerical data, Radiotherapy, Conformal methods, Rectal Diseases prevention & control, Risk Factors, Treatment Outcome, Tumor Burden radiation effects, Gastrointestinal Hemorrhage epidemiology, Prostatic Neoplasms epidemiology, Prostatic Neoplasms radiotherapy, Radiation Protection methods, Radiotherapy, Conformal statistics & numerical data, Rectal Diseases epidemiology
- Abstract
In patients undergoing radiotherapy for localized prostate cancer, dose-volume histograms and clinical variables were examined to search for correlations between radiation treatment planning parameters and late rectal bleeding. We analyzed 129 patients with localized prostate cancer who were managed from 2002 to 2010 at our institution. They were treated with 3D conformal radiation therapy (3D-CRT, 70 Gy/35 fractions, 55 patients) or intensity-modulated radiation therapy (IMRT, 76 Gy/38 fractions, 74 patients). All radiation treatment plans were retrospectively reconstructed, dose-volume histograms of the rectum were generated, and the doses delivered to the rectum were calculated. Time to rectal bleeding ranged from 9-53 months, with a median of 18.7 months. Of the 129 patients, 33 patients had Grade 1 bleeding and were treated with steroid suppositories, while 25 patients with Grade 2 bleeding received argon plasma laser coagulation therapy (APC). Three patients with Grade 3 bleeding required both APC and blood transfusion. The 5-year incidence rate of Grade 2 or 3 rectal bleeding was 21.8% for the 3D-CRT group and 21.6% for the IMRT group. Univariate analysis showed significant differences in the average values from V65 to V10 between Grades 0-1 and Grades 2-3. Multivariate analysis demonstrated that patients with V65 ≥ 17% had a significantly increased risk (P = 0.032) of Grade 2 or 3 rectal bleeding. Of the 28 patients of Grade 2 or 3 rectal bleeding, 17 patients (60.7%) were cured by a single session of APC, while the other 11 patients required two sessions. Thus, none of the patients had any further rectal bleeding after the second APC session., (© The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.)
- Published
- 2015
- Full Text
- View/download PDF
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