11 results on '"Sotaro Izumi"'
Search Results
2. Precise patient selection for hip arthroscopy using ultrasound-guided hip injection
- Author
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Takuma Yamasaki, Susumu Hachisuka, Takeshi Shoji, Sotaro Izumi, Hiroaki Murakami, Seiichiro Niimoto, Mikiya Sawa, Kenji Mifuji, Yuji Yasunaga, Nobuo Adachi, and Mitsuo Ochi
- Subjects
Sports medicine ,RC1200-1245 - Published
- 2016
- Full Text
- View/download PDF
3. Rotational Acetabular Osteotomy for Pre- and Early Osteoarthritis Secondary to Dysplasia Provides Durable Results at 20 Years
- Author
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Sotaro Izumi, Takeshi Shoji, Mitsuo Ochi, Yuji Yasunaga, and Takuma Yamasaki
- Subjects
Adult ,Male ,musculoskeletal diseases ,medicine.medical_specialty ,Time Factors ,Adolescent ,medicine.medical_treatment ,Kaplan-Meier Estimate ,Osteoarthritis ,Osteotomy ,Osteoarthritis, Hip ,CORR Insights ,Young Adult ,03 medical and health sciences ,Femoral head ,Postoperative Complications ,0302 clinical medicine ,Risk Factors ,medicine ,Hip Dislocation ,Humans ,Orthopedics and Sports Medicine ,Pelvis ,Proportional Hazards Models ,Retrospective Studies ,Hip dysplasia ,Hip surgery ,030222 orthopedics ,business.industry ,Hazard ratio ,Age Factors ,Acetabulum ,Recovery of Function ,030229 sport sciences ,General Medicine ,Middle Aged ,medicine.disease ,Biomechanical Phenomena ,Surgery ,Early Diagnosis ,Treatment Outcome ,medicine.anatomical_structure ,Orthopedic surgery ,Disease Progression ,Female ,Hip Joint ,business - Abstract
Hip dysplasia is a common cause of secondary osteoarthritis (OA). Periacetabular osteotomy or rotational acetabular osteotomy has been used as joint-preserving procedures. However, only a few reports of long-term results with these operations have been reported. (1) Would satisfactory clinical and radiographic outcomes be maintained at a mean duration of 20 years after rotational acetabular osteotomy for pre- and early-stage OA; and (2) could we identify risk factors for radiographic progression of OA? Between 1987 and 2001, we treated 159 patients (173 hips) with rotational acetabular osteotomies for the diagnosis of pre-OA or early-stage OA according to the technique of Ninomiya and Tagawa. During that period, our general indications for this approach were age younger than 60 years, center-edge angle less than 20°, and improved femoral head coverage and joint congruency on preoperative AP plain radiographs of the hip in abduction; we did not use this approach when joint congruency was not improved or no widening of the joint space was noted on preoperative AP plain radiographs of the hip in abduction. Of those patients, 21 patients with pre-OA (followup rate: 84% [27 hips]) and 110 patients in the early-stage group (followup rate: 82% [118 hips]) were available at a minimum of 15 years for a total patient group of 131 (followup rate: 82% [145 hips]). The mean age at the time of surgery was 22 years in the pre-OA group and 38 years in the early-stage group. The mean followup was 21 years in the pre-OA group and 20 years in the early-stage group. Clinical evaluation was performed with the Merle d’Aubigne and Postel rating scale, and radiographic analyses included measurements of the center-edge angle, acetabular roof angle, and head lateralization index on preoperative and postoperative AP radiographs of the pelvis. Postoperative joint congruency was also evaluated. The cumulative probabilities of radiographic signs of OA progression were estimated with use of the Kaplan-Meier product-limited method and parametric survivorship analysis using the Cox proportional-hazards model was used to determine risk factors for radiographic OA progression. The mean clinical score improved very slightly, from 15 (SD, 0.8) to 18 (SD, 1.1) (95% confidence interval [CI], −2.9 to −2.0; p < 0.001) in the pre-OA group and from 15 (SD, 1.0) to 16 (SD, 2.1) (95% CI, −2.0 to −1.2; p < 0.001) in the early-stage group at followup. Fourteen patients (15 hips) including one pre-OA patient (one hip) and 13 early-stage patients (14 hips) experienced worsening of their Merle d’Aubigne and Postel score, from a mean of 15 (SD, 0.9) to 12 (SD, 1.6) (95% CI, 1.8–3.3; p < 0.001). Eight patients (nine hips) with early-stage OA preoperatively underwent total hip arthroplasty at a mean duration after rotational acetabular osteotomy of 20 (SD, 2.5) years. Radiographic indices were improved after surgery in both groups. Radiographic progression of OA occurred in 24 patients (25 hips). Kaplan-Meier survivorship analysis, with radiographic signs of progression of OA as the endpoint, predicted survival of 96% (95% CI, 89%–100%) at 10 years and 20 years in the pre-OA group. For the early-stage group, we found survivorship of 89% (95% CI, 83%–95%) at 10 years and 78% (95% CI, 69%–87%) at 20 years. We identified two factors associated with poor outcome: fair (rather than excellent and good) postoperative joint congruency (hazard ratio, 12.1; 95% CI, 3.8–39; p < 0.001) and age older than 46 years at the time of surgery (hazard ratio, 4.6; 95% CI, 1.9–11; p < 0.01). Rotational acetabular osteotomy is an effective surgical procedure for symptomatic dysplastic hips in pre- and early-stage OA, and it prevented radiographic OA progression and maintained hip function at a mean 20 years after surgery. Level IV, therapeutic study.
- Published
- 2016
4. Introduction to Deep Learning by using R
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Jinghao Ma, Wanqiu Song, and Sotaro Izumi
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- 2020
5. Ultraviolet-emitting ZnO thick layer grown by thermal oxidation with gallium
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Atsushi Tackeuchi, Xiaohong Zhou, Takao Nukui, Hirokazu Tatsuoka, Sotaro Izumi, Qing Yang, Shu Hua Liang, and Yu Saeki
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Thermal oxidation ,Photoluminescence ,Materials science ,Exciton ,General Engineering ,Optical property ,chemistry.chemical_element ,Substrate (electronics) ,medicine.disease_cause ,Photochemistry ,chemistry ,medicine ,General Materials Science ,Gallium ,Layer (electronics) ,Ultraviolet - Abstract
The ZnO layer with thickness of 1.6 μm in ZnO/ZnGa2O4 composite structure was grown by the thermal oxidation of ZnS substrate with gallium. The optical property of the ZnO thick layer was investigated by time-resolved photoluminescence. A single UV emission around 375 nm with short lifetime was observed at room temperature while the visible emission was absolutely quenched. The UV emission band was composed of the neutral donor bound exciton (D0X) and donor-acceptor pair (DAP) emission peaks with large full-width at half-maximums (FWHMs) at 3.367 and 3.318 eV, respectively, at 10 K. However, the intensity of the D0X emission was stronger than that of the DAP emission at measuring temperatures of 10–300 K.
- Published
- 2014
6. Novel ultraviolet photoluminescence of ZnO/ZnGa2O4 composite layers
- Author
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Atsushi Tackeuchi, Akihiro Ishida, Takao Nukui, Yu Saeki, Sotaro Izumi, Qing Yang, and Hirokazu Tatsuoka
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Thermal oxidation ,Materials science ,Photoluminescence ,Scanning electron microscope ,Composite number ,General Physics and Astronomy ,chemistry.chemical_element ,Mineralogy ,Surfaces and Interfaces ,General Chemistry ,Zinc ,Condensed Matter Physics ,medicine.disease_cause ,Surfaces, Coatings and Films ,chemistry ,Chemical engineering ,medicine ,Gallium ,Layer (electronics) ,Ultraviolet - Abstract
ZnO/ZnGa 2 O 4 composite layers were synthesized by simple thermal oxidation of ZnS substrates with gallium in the air. The continuous-wave and time-resolved photoluminescence measurements for the composites were performed at room temperature. It is found that the visible deep level emission from ZnO in ZnO/ZnGa 2 O 4 composite layer was almost suppressed. In addition, the UV emission with long lifetime was also observed in comparison with that of pure ZnO layer without ZnGa 2 O 4 .
- Published
- 2010
7. Inclusion and Exclusion Criteria in the Diagnosis of Femoroacetabular Impingement
- Author
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Mitsuo Ochi, Takuma Yamasaki, Sotaro Izumi, Takeshi Shoji, Susumu Hachisuka, and Yuji Yasunaga
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Orthodontics ,medicine.medical_specialty ,business.industry ,Radiography ,Ischial spine ,Acetabulum ,medicine.disease ,Femoracetabular Impingement ,Ischium ,Surgery ,medicine.anatomical_structure ,Inclusion and exclusion criteria ,medicine ,Humans ,Orthopedics and Sports Medicine ,business ,Acetabular index ,Femoroacetabular impingement - Abstract
Purpose The purpose of this study was to clarify the criteria for femoroacetabular impingement (FAI) by way of a systematic review of FAI-related articles, as well as to define more appropriate inclusion or exclusion criteria in the diagnosis of FAI. Methods A systematic review of FAI-related articles was performed using Web of Science. Thirty-two articles met the inclusion and exclusion criteria. In these articles we investigated radiographic findings for the diagnosis of FAI and the prevalence of each FAI-related finding. Results The crossover sign was used in 22 articles (69%); acetabular index, 9 articles (28%); posterior wall sign, 7 articles (22%); and prominence of the ischial spine sign, 3 articles (7%). Regarding acetabular coverage, the lateral center-edge (LCE) angle was described in 13 articles (41%), in which an LCE angle either of more than 40° or of more than 30° combined with an acetabular index of less than 0° was considered an inclusion criterion for pincer impingement. Meanwhile, the alpha angle was used in 28 articles (88%), in which 50° or 55° was recommended as a positive finding of cam impingement. Conclusions Common findings of pincer or cam deformity were used to select FAI patients with sufficient coverage of the acetabulum with an LCE angle of more than 25°. Patients with an LCE angle of less than 25° or those with local acetabular deficiency regardless of having a normal LCE angle should be excluded from the FAI criteria, even if the FAI-related findings are positive. Level of Evidence Level IV, systematic review of Level I through IV studies.
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- 2014
8. Time-resolved ultraviolet photoluminescence of ZnO/ZnGa2O4 composite layer
- Author
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Shuhua Liang, Hirokazu Tatsuoka, Takao Nukui, Yu Saeki, Sotaro Izumi, Qing Yang, Xiaohong Zhou, and Atsushi Tackeuchi
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Thermal oxidation ,Materials science ,Photoluminescence ,business.industry ,Inorganic chemistry ,Composite number ,Wide-bandgap semiconductor ,General Physics and Astronomy ,chemistry.chemical_element ,medicine.disease_cause ,lcsh:QC1-999 ,chemistry ,medicine ,Optoelectronics ,Photoluminescence excitation ,Gallium ,business ,Layer (electronics) ,lcsh:Physics ,Ultraviolet - Abstract
The ultraviolet photoluminescence of ZnO/ZnGa2O4 composite layer grown by the thermal oxidation of ZnS with gallium was investigated by the time-resolved photoluminescence as a function of measuring temperature and excitation power. With increase of excitation power, the D0X emission is easily saturated than the DAP emission from ZnO/ZnGa2O4 composite layer, and which is dramatically enhanced as compared with that from pure ZnO layer grown without gallium. The radiative recombination process with ultra-long lifetime controlled the carrier recombination of ZnO/ZnGa2O4 composite layer.
- Published
- 2014
9. Picosecond Carrier Recombination of Single-Crystalline GaN Nanorods Grown on Si(111) Substrates
- Author
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Tae Won Kang, Chan Ho Yoo, Yoshiaki Nakazato, Young Hae Kwon, Sotaro Izumi, Takao Nukui, Atsushi Tackeuchi, Taisuke Fujita, Tae Whan Kim, and Yu Saeki
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Photoluminescence ,Materials science ,business.industry ,Hydride ,General Engineering ,General Physics and Astronomy ,Epitaxy ,Catalysis ,Picosecond ,Optoelectronics ,Nanorod ,business ,Recombination ,Wurtzite crystal structure - Abstract
Time-resolved photoluminescence measurement was performed on one-dimensional GaN nanorods with c-axis-oriented single-crystalline wurtzite structures. The GaN nanorods were grown on Si(111) substrates by an improved hydride vapor phase epitaxy without a catalyst. Fast carrier recombinations of less than 10 ps were observed. The short recombination times of the GaN nanorods with few defects show the presence of nonradiative fast recombinations at the surface and interface.
- Published
- 2010
10. Observation of Spin Relaxation in InGaAs/AlAsSb Quantum Wells
- Author
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Yu Saeki, Sotaro Izumi, Takao Nukui, Teruo Mozume, Shin Ichiro Gozu, and Atsushi Tackeuchi
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Physics ,Materials science ,Condensed matter physics ,Spin polarization ,Condensed Matter::Other ,Exciton ,General Engineering ,General Physics and Astronomy ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Spin relaxation time ,Reflectivity ,Condensed Matter::Materials Science ,Charge-carrier density ,Spin relaxation ,Quantum well ,Excitation - Abstract
We have investigated the exciton spin relaxation in InGaAs/AlAsSb quantum wells using time-resolved spin-dependent pump and probe reflectance measurements. The spin relaxation time of 1.46 µm electron-heavy hole excitons at room temperature is obtained to be 27–54 ps for an excitation power of 20–100 mW. The carrier density dependence of the exciton spin relaxation time was clearly observed, suggesting that the spin relaxation mechanism is strongly related to the Bir–Aronov–Pikus process at room temperature.
- Published
- 2010
11. Time-resolved ultraviolet photoluminescence of ZnO/ZnGa2O4 composite layer.
- Author
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Qing Yang, Xiaohong Zhou, Takao Nukui, Yu Saeki, Sotaro Izumi, Atsushi Tackeuchi, Hirokazu Tatsuoka, and Shuhua Liang
- Subjects
PHOTOLUMINESCENCE ,THERMAL oxidation (Materials science) ,GALLIUM ,ZINC oxide ,MATERIALS science - Abstract
The ultraviolet photoluminescence of ZnO/ZnGa
2 O4 composite layer grown by the thermal oxidation of ZnS with gallium was investigated by the time-resolved photoluminescence as a function of measuring temperature and excitation power. With increase of excitation power, the D0X emission is easily saturated than the DAP emission from ZnO/ZnGa2 O4 composite layer, and which is dramatically enhanced as compared with that from pure ZnO layer grown without gallium. The radiative recombination process with ultra-long lifetime controlled the carrier recombination of ZnO/ZnGa2 O4 composite layer. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
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