Search

Your search keyword '"Oba, Hiroki"' showing total 470 results
Start Over Author "Oba, Hiroki"
470 results on '"Oba, Hiroki"'

1. Scaling laws for velocity profile of granular flow in rotating drums

Author

Oba, Hiroki and Otsuki, Michio

Subjects
Condensed Matter - Soft Condensed Matter, Condensed Matter - Statistical Mechanics
Abstract

We numerically analyze the steady flow of two-dimensional granular materials in a rotating drum using the discrete element method and a continuum model. The velocity fields obtained from both methods are quantitatively consistent. Two distinct regions exist in the granular flow: the surface flow layer and the static flow regime associated with the rigid rotation near the bottom. The thickness of the surface flow layer increases with the drum diameter and shows a slight dependence on the angular velocity of the rotating drum. Scaling laws for the velocity profile and the surface layer thickness are derived analytically based on the continuum model. The validity of the scaling laws is confirmed numerically.

Published
2024

3. Zones where reduced implant density leads to correction loss after scoliosis surgery for Lenke 1A adolescent idiopathic scoliosis: a multicenter study

Author

Yanagisawa, Kaho, Oba, Hiroki, Ohba, Tetsuro, Banno, Tomohiro, Seki, Shoji, Uehara, Masashi, Ikegami, Shota, Mimura, Tetsuhiko, Hatakenaka, Terue, Miyaoka, Yoshinari, Kurogochi, Daisuke, Fukuzawa, Takuma, Koseki, Michihiko, Kawaguchi, Yoshiharu, Haro, Hirotaka, Matsuyama, Yukihiro, and Takahashi, Jun

Published
2024
Full Text
View/download PDF

5. Excessive posterior placement of upper instrumented vertebra relative to lower instrumented vertebra as a predictor of proximal junction kyphosis after selective spinal fusion for adolescent idiopathic scoliosis Lenke type 5C curves

Author

Oba, Hiroki, Banno, Tomohiro, Ohba, Tetsuro, Ikegami, Shota, Uehara, Masashi, Mimura, Tetsuhiko, Koseki, Michihiko, Hatakenaka, Terue, Miyaoka, Yoshinari, Kurogochi, Daisuke, Fukuzawa, Takuma, Sasao, Shinji, Matsuyama, Yukihiro, Haro, Hirotaka, and Takahashi, Jun

Published
2024
Full Text
View/download PDF

21. Factors Affecting the Waiting Time from Injury to Surgery in Elderly Patients with a Cervical Spine Injury: A Japanese Multicenter Survey

Author

Uehara, Masashi, Ikegami, Shota, Takizawa, Takashi, Oba, Hiroki, Yokogawa, Noriaki, Sasagawa, Takeshi, Ando, Kei, Nakashima, Hiroaki, Segi, Naoki, Funayama, Toru, Eto, Fumihiko, Yamaji, Akihiro, Watanabe, Kota, Nori, Satoshi, Takeda, Kazuki, Furuya, Takeo, Yunde, Atsushi, Nakajima, Hideaki, Yamada, Tomohiro, Hasegawa, Tomohiko, Terashima, Yoshinori, Hirota, Ryosuke, Suzuki, Hidenori, Imajo, Yasuaki, Tonomura, Hitoshi, Sakata, Munehiro, Hashimoto, Ko, Onoda, Yoshito, Kawaguchi, Kenichi, Haruta, Yohei, Suzuki, Nobuyuki, Kato, Kenji, Uei, Hiroshi, Sawada, Hirokatsu, Nakanishi, Kazuo, Misaki, Kosuke, Terai, Hidetomi, Tamai, Koji, Shirasawa, Eiki, Inoue, Gen, Kakutani, Kenichiro, Kakiuchi, Yuji, Kiyasu, Katsuhito, Tominaga, Hiroyuki, Tokumoto, Hiroto, Iizuka, Yoichi, Takasawa, Eiji, Akeda, Koji, Takegami, Norihiko, Funao, Haruki, Oshima, Yasushi, Kaito, Takashi, Sakai, Daisuke, Yoshii, Toshitaka, Otsuki, Bungo, Seki, Shoji, Miyazaki, Masashi, Ishihara, Masayuki, Okada, Seiji, Imagama, Shiro, and Kato, Satoshi

Published
2022
Full Text
View/download PDF

23. Usefulness of modified S-line for upper instrumented vertebra selection in adolescent idiopathic scoliosis Lenke type 2 curves

Author

Mimura, Tetsuhiko, Ikegami, Shota, Banno, Tomohiro, Seki, Shoji, Ohba, Tetsuro, Oba, Hiroki, Kuraishi, Shugo, Uehara, Masashi, Munakata, Ryo, Takizawa, Takashi, Hatakenaka, Terue, Kamanaka, Takayuki, Miyaoka, Yoshinari, Kurogochi, Daisuke, Fukuzawa, Takuma, Haro, Hirotaka, Kawaguchi, Yoshiharu, Matsuyama, Yukihiro, Koseki, Michihiko, and Takahashi, Jun

Published
2022
Full Text
View/download PDF

32. The Validation Of The Japanese Version Of The Scoliosis Research Society-30 Questionnaire For Adolescent Idiopathic Scoliosis Patients

Author

Arima, Hideyuki, primary, Yamato, Yu, additional, Shibata, Yosuke, additional, Oba, Hiroki, additional, Takahashi, Jun, additional, Watanabe, Kei, additional, Sugawara, Ryo, additional, Takeshita, Katsushi, additional, Omura, Takao, additional, Carreon, Leah, additional, Arai, Yasuhisa, additional, Asada, Tomoyuki, additional, Demura, Satoru, additional, Doi, Toru, additional, Matsumura, Akira, additional, Suzuki, Satoshi, additional, Takahashi, Shinji, additional, Takeuchi, Takumi, additional, Ueda, Haruki, additional, and Hosogane, Naobumi, additional

Published
2024
Full Text
View/download PDF

33. Is Intraoperative Blood Loss Volume in Elderly Cervical Spine Injury Surgery Greater in Patients with Ankylosis? A Multicenter Survey

Author

Uehara, Masashi, primary, Ikegami, Shota, additional, Takizawa, Takashi, additional, Oba, Hiroki, additional, Yokogawa, Noriaki, additional, Sasagawa, Takeshi, additional, Nakashima, Hiroaki, additional, Segi, Naoki, additional, Ito, Sadayuki, additional, Funayama, Toru, additional, Eto, Fumihiko, additional, Yamaji, Akihiro, additional, Watanabe, Kota, additional, Nori, Satoshi, additional, Takeda, Kazuki, additional, Furuya, Takeo, additional, Yunde, Atsushi, additional, Nakajima, Hideaki, additional, Yamada, Tomohiro, additional, Hasegawa, Tomohiko, additional, Terashima, Yoshinori, additional, Hirota, Ryosuke, additional, Suzuki, Hidenori, additional, Imajo, Yasuaki, additional, Tonomura, Hitoshi, additional, Sakata, Munehiro, additional, Hashimoto, Ko, additional, Onoda, Yoshito, additional, Kawaguchi, Kenichi, additional, Haruta, Yohei, additional, Suzuki, Nobuyuki, additional, Kato, Kenji, additional, Uei, Hiroshi, additional, Sawada, Hirokatsu, additional, Nakanishi, Kazuo, additional, Misaki, Kosuke, additional, Terai, Hidetomi, additional, Tamai, Koji, additional, Kuroda, Akiyoshi, additional, Inoue, Gen, additional, Kakutani, Kenichiro, additional, Kakiuchi, Yuji, additional, Kiyasu, Katsuhito, additional, Tominaga, Hiroyuki, additional, Tokumoto, Hiroto, additional, Iizuka, Yoichi, additional, Takasawa, Eiji, additional, Akeda, Koji, additional, Takegami, Norihiko, additional, Funao, Haruki, additional, Oshima, Yasushi, additional, Kaito, Takashi, additional, Sakai, Daisuke, additional, Yoshii, Toshitaka, additional, Ohba, Tetsuro, additional, Otsuki, Bungo, additional, Seki, Shoji, additional, Miyazaki, Masashi, additional, Ishihara, Masayuki, additional, Okada, Seiji, additional, Imagama, Shiro, additional, and Kato, Satoshi, additional

Published
2024
Full Text
View/download PDF

34. A case of adult-onset Grisel's syndrome.

Author

Nakai, Ami, Uehara, Masashi, Miyaoka, Yoshinari, Oba, Hiroki, Ikegami, Shota, Takizawa, Takashi, Munakata, Ryo, Hatakenaka, Terue, Kamanaka, Takayuki, Kurogochi, Daisuke, Fukuzawa, Takuma, and Takahashi, Jun

Subjects
ATLANTO-axial joint, JOINT stiffness, SPINAL cord compression, MAGNETIC resonance imaging, DIAGNOSIS, NECK pain, SPONDYLITIS
Abstract

Aim: Grisel's syndrome is a non-traumatic subluxation of the atlanto-axial joint that occurs after infection or inflammation in the otolaryngological area, primarily in children. Method: This report describes the clinical characteristics of an extremely rare case of adult-onset Grisel's syndrome. Result: A 77-year-old woman presented with neck and bilateral shoulder pain and stiffness. Her temperature was 37.6 °C. Blood testing revealed a mildly elevated inflammatory response, although blood cultures were negative. Computed tomography (CT) showed atlanto-axial subluxation and joint destruction. T2-weighted magnetic resonance imaging (MRI) displayed high signals in the soft tissues in the anterior space of the atlas and axis, posterior wall of the pharynx, and interspinous ligament, indicating spinal cord compression at the C1 level. Differential diagnoses of inflammation and diseases causing atlanto-axial subluxation included rheumatoid arthritis, amyloidosis, pyogenic spondylitis due to posterior pharyngeal abscess, and crowned dens syndrome. After the systematic elimination of each condition, we considered Grisel's syndrome and began non-surgical treatment with intravenous antibiotics and a Philadelphia neck collar. Her inflammatory response and neck pain gradually decreased. Six months later, there was no progression of instability. She was able to walk unaided and live normally with the use of a neck collar as needed. Conclusion: Grisel's syndrome occurs predominantly in children, but can also afflict adults. Since early diagnosis and treatment can improve symptoms in some cases and prevent progressive atlanto-axial instability, prompt evaluation of the atlanto-axial joint using CT or MRI is advised in patients with neck pain and limited range of motion. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

40. Pseudohypoxic brain swelling and secondary hydrocephalus with pseudomeningocele after lumbar surgery: a case report.

Author

Miyaoka, Yoshinari, Uehara, Masashi, Oba, Hiroki, Kamanaka, Takayuki, Ikegami, Shota, Kuraishi, Shugo, Futatsugi, Toshimasa, Tsutsumimoto, Takahiro, Kaneko, Tomoki, Fujinaga, Yasunari, Nakao, Satoshi, Kodaira, Minori, Sekijima, Yoshiki, Maruyama, Takahiro, Hamano, Yujiro, Ichikawa, Michitaro, Imamura, Hiroshi, Kuroiwa, Masafumi, Horiuchi, Tetsuyoshi, and Tanaka, Satoshi

Subjects
SPINAL surgery, HYDROCEPHALUS, CEREBRAL anoxia-ischemia, LUMBAR vertebrae, CEREBROSPINAL fluid, HYPEREMIA, EDEMA
Abstract

Postoperative intracranial complications are rare in spine surgery not including cranial procedures. We describe an uncommon case of pseudohypoxic brain swelling (PHBS) and secondary hydrocephalus after transforaminal lumbar interbody fusion (TLIF) presenting as impaired consciousness and repeated seizures. A 65-year-old man underwent L4-5 TLIF for lumbar spondylolisthesis and began experiencing generalized seizures immediately postoperatively. Computed tomography (CT) revealed diffuse cerebral edema-like hypoxic ischemic encephalopathy. He was transported to our hospital, at which time epidural drainage was halted and anti-edema therapy was commenced. His impaired consciousness improved. However, he suffered secondary hydrocephalus due to continuous bleeding from a dural defect and spinal epidural fluid collection 3 months later. Following the completion of dural repair and insertion of a ventriculoperitoneal shunt, his neurologic symptoms and neuroimaging findings improved significantly. PHBS can be considered in patients with unexpected neurological deterioration following lumbar spine surgery even with the absence of documented durotomy. This might be due to postoperative intracranial hypotension-associated venous congestion, and to be distinguished from the more common postoperative cerebral ischemic events–caused by arterial or venous occlusions–or anesthetics complications. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results