Solid-State Characterization of Polythylene Reactor Powders and Their Structural Changes upon Annealing

Hiroki Uehara,Ayako Uehara,Masaki Kakiage,Hiroshi Takahashi,Syozo Murakami,Taleshi Yamanbe 한국고분자학회 2007 한국고분자학회 학술대회 연구논문 초록집 Vol.2007 No.4

An Assistive Robot Arm System for People with Disabilities : Availability of Motion Generation Tool

Hiroki Higa,Hideyuki Uehara,Katsuya Taira 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

An assistive robot arm for people with disabilities was described in this paper. The system is composed of a robot arm, PC, control device, and driver. To generate input signals for any motions of the assistive robot arm easily, we also made the motion generation tool which had five links and five variable resistors to detect changes in angles between each link, and the outputs of the variable resistors connected to the dc power supply were sampled by the PC through AD converter. Using the device, we obtained the motions of the eating commands. They were conducted by three experimental subjects and the experimental results showed that using the assistive robot arm system they could eat fried chickens properly.

Mid-Term Results of Computer-Assisted Cervical Pedicle Screw Fixation

Masashi Uehara,Jun Takahashi,Keijiro Mukaiyama,Shugo Kuraishi,Masayuki Shimizu,Shota Ikegami,Toshimasa Futatsugi,Nobuhide Ogihara,Hiroyuki Hashidate,Hiroki Hirabayashi,Hiroyuki Kato 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6

Study Design: A retrospective study. Purpose: The present study aimed to evaluate mid-term results of cervical pedicle screw (CPS) fixation for cervical instability. Overview of Literature: CPS fixation has widely used in the treatment of cervical spinal instability from various causes; however, there are few reports on mid-term surgical results of CPS fixation. Methods: Record of 19 patients who underwent cervical and/or upper thoracic (C2–T1) pedicle screw fixation for cervical instability was reviewed. The mean observation period was 90.2 months. Evaluated items included Japanese Orthopaedic Association (JOA) score and C2–7 lordotic angle before surgery and at 5 years after surgery. Postoperative computerized tomography was used to determine the accuracy of screw placement. Visual analog scale (VAS) for neck pain and radiological evidence of adjacent segment degeneration (ASD) at the 5-year follow-up were also evaluated. Results: Mean JOA score was significantly improved from 9.0 points before surgery to 12.8 at 5 years after surgery (p =0.001). The C2–7 lordotic angle of the neutral position improved from 6.4° to 7.8° at 5 years after surgery, but this was not significant. The major perforation rate was 5.0%. There were no clinically significant complications such as vertebral artery injury, spinal cord injury, or nerve root injury caused by any screw perforation. Mean VAS for neck pain was 49.4 at 5 years after surgery. The rate of ASD was 21.1%. Conclusions: Our mid-term results showed that CPS fixation was useful for treating cervical instability. Severe complications were prevented with the assistance of a computed tomography-based navigation system.

Comparison of Spinous Process-Splitting Laminectomy versus Conventional Laminectomy for Lumbar Spinal Stenosis

Masashi Uehara,Jun Takahashi,Hiroyuki Hashidate,Keijiro Mukaiyama,Shugo Kuraishi,Masayuki Shimizu,Shota Ikegami,Toshimasa Futatsugi,Nobuhide Ogihara,Hiroki Hirabayashi,Hiroyuki Kato 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6

Study Design: Seventy-five patients who had been treated for lumbar spinal stenosis (LSS) were reviewed retrospectively. Purpose: Invasion into the paravertebral muscle can cause major problems after laminectomy for LSS. To address these problems, we performed spinous process-splitting laminectomy. We present a comparative study of decompression of LSS using 2 approaches. Overview of Literature: There are no other study has investigated the lumbar spinal instability after spinous process-splitting laminectomy. Methods: This study included 75 patients who underwent laminectomy for the treatment of LSS and who were observed through follow-ups for more than 2 years. Fifty-five patients underwent spinous process-splitting laminectomy (splitting group) and 20 patients underwent conventional laminectomy (conventional group). We evaluated the clinical and radiographic results of each surgical procedure. Results: Japanese Orthopaedic Association score improved significantly in both groups two years postoperatively. The following values were all significantly lower, as shown with p -values, in the splitting group compared to the conventional group: average operating time (p =0.002), postoperative C-reactive protein level (p =0.006), the mean postoperative number of days until returning to normal body temperature (p =0.047), and the mean change in angulation 2 years postoperatively (p =0.007). The adjacent segment degeneration occurred in 6 patients (10.9%) in the splitting group and 11 patients (55.0%) in the conventional group. Conclusions: In this study, the spinous process-splitting laminectomy was shown to be less invasive and more stable for patients with LSS, compared to the conventional laminectomy.

Mini Open Foraminotomy for Cervical Radiculopathy: A Comparison of Large Tubular and TrimLine Retractors

Masashi Uehara,Jun Takahashi,Shugo Kuraishi,Masayuki Shimizu,Shota Ikegami,Toshimasa Futatsugi,Kaoru Aoki,Keijiro Mukaiyama,Nobuhide Ogihara,Hiroyuki Hashidate,Hiroki Hirabayashi,Hiroyuki Kato 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.4

Study Design: Retrospective chart review. Purpose: A comparison of mini open foraminotomy (MOF) for cervical radiculopathy using either large tubular (LT) or TrimLine (TL) retractors. Overview of Literature: Posterior foraminotomy relieves compression of the cervical nerve root in radiculopathy patients. However, invasion of the paravertebral muscle may cause major problems in these patients. To address these problems, we performed MOF. Methods: Twenty cervical radiculopathy patients (16 male and 4 female) who underwent MOF between May 2004 and August 2011 were assigned to LT and TL groups. Each group contained 10 subjects. Surgical and clinical outcomes were compared. Results: The average operating time in the TL group was significantly shorter than that in the LT group. The final follow-up mean neck disability indices significantly improved compared to the preoperative values (LT group, 12.0±7.8 vs. 28.0±9.4; TL group, 6.0±5.9 vs. 21.9±10). The final follow-up neck pain visual analog scale (VAS) scores also decreased significantly from the preoperative of 8.0±1.5 and 2.5±2.5 to the final follow-up values of 2.2±2.2 and 1.0±2.5 in the LT and TL groups, respectively. The recovery rate for the neck pain VAS score was 70.0±31.9 in the LT group and 87.0±32.0 in the TL group, thus suggesting no significant difference between the two groups. Conclusions: MOF with the TL retractor is an easy and safe procedure. Furthermore, the use of the TL retractor allows for a minimally invasive and effective surgical treatment of cervical radiculopathy patients.

Effect of Carotenoides on the in vitro Aggregation of Bacteriochlorophyll e

Hirabayashi, Hiroki,Ohmura, Satoshi,Ishii, Takasada,Uehara, Kaku Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

In order to investigate effect of the carotenoids (Car) on aggregation of Bacterochlorophyll (BChl) in chlorosome, we studied the spectral difference in aggregates of BChl e formed in the absence and presence of a few kinds of Car in dimethyl sulfoxide (DMSO) -water solution. The absorption spectra of aggregates made of only BChl e and those made of a mixture of BChl e and Car were almost the same. However, the kinetics and circular dichroism (CD) spectra of aggregate of these were markedly different by kind of Car. Specifically, the rate of aggregation for a mixture of BChl e and isorenietene that contains phenyl as end groupe was faster than that for only BChl e. CD spectra of aggregates made of a mixture of BChl e and isorenietene dramatically changed compared to that made of only BChl e. We propose that BChl might form several kinds of rod-like supramolecular structures to in the presence of some kind of Car in chlorosome.

Photoadaptation of Green Sulfur Photosynthetic Bacteria Chlorobium phaeobacteroides

Hirabayashi, Hiroki,Ohmura, Satoshi,Ishii, Takasada,Takaichi, Shinichi,Uehara, Kaku Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

Photoadaptation of Chlorobium (Cb.) phaeobacteroides was investigated under dim and strong light intensity. Absorption spectra of these whole cellIs were different each other. The Soret band intensity and the Qy bandwidth of BChl e in c디l grown under dim light intensity were smaller and more broadened than those under strong light intensity. From HPLC analysis of the pigments, total carotenoid (Car) / bacterochorolphyll (BChl) e ratio of cell increased wi1h increase of light intensities. But camposition of BChl e hamologs almost unchanged. Cb. phaeobacteroides contains 11 kinds of Car including isorenieratene and beta-isorenieratene as major Car. The campositions of Car were different for cells grown under dim and strong light intensities. In conclusion, Cb. phaeobacteroides changes total amount and canposition of Car to adapt various light intensities, while homolog canposition of BChle unchange.

Postoperative Residual Coronal Decompensation Inhibits Self-image Improvement in Adolescent Patients with Idiopathic Scoliosis

Higuchi Shohei,Ikegami Shota,Oba Hiroki,Uehara Masashi,Kuraishi Shugo,Takizawa Takashi,Munakata Ryo,Hatakenaka Terue,Kamanaka Takayuki,Miyaoka Yoshinari,Koseki Michihiko,Mimura Tetsuhiko,Takahashi Jun 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.1

Study Design: Retrospective cohort study.Purpose: This study aimed to evaluate the relationship between C7 plumb line (C7PL) decompensation and the Scoliosis Research Society (SRS) 22-item patient questionnaire scores, including those related to self-image, preoperatively and 2 years after surgery.Overview of Literature: In the surgical treatment of adolescent idiopathic scoliosis (AIS), inferior trunk balance caused by C7PL decompensation can negatively affect patients’ quality of life. However, there are few reports in the literature that describe or clarify how postoperative trunk imbalance affects each SRS-22 domain, including self-image domain scores.Methods: A total of 120 patients with AIS who underwent posterior spinal fusion from August 2006 to March 2017 at our facility and were followed up for 2 years or more were included. Radiological parameters were measured on whole-spine anteroposterior and lateral radiographs. Revised SRS-22 (SRS-22r) values were also recorded. Coronal trunk imbalance was defined as a deviation of ≥2.0 cm between the C7PL and the central sacral vertical line. Patients with and without coronal trunk imbalance at 2 years after surgery were defined as D (+) (decompensation type) and D (-), respectively. Mean SRS-22r values, including function, pain, self-image, mental health, and subtotal were compared between the D (+) and D (-) groups. Logistic regression analysis was performed to detect the preoperative factors related to D (+) using predictors, including curve type, maximum Cobb angle, and coronal trunk imbalance.Results: At 2 years after surgery, the D (+) group had a significantly lower self-image in the domain of SRS-22r scores compared with the D (-) group. Preoperative coronal trunk imbalance was significantly related to D (+) but not to significant changes in the postoperative SRS-22 score in any of the SRS-22 domains.Conclusions: Postoperative C7PL deviation lowers the self-image in patients with AIS. Patients with preoperative coronal trunk imbalance were significantly more likely to be D (+).

Ten-Year Results of Reconstruction for Rheumatoid Cervical Spine Lesions and Occurrence Factor of Subaxial Subluxation

Daisuke Kurogochi,Jun Takahashi,Masashi Uehara,Shota Ikegami,Shugo Kuraishi,Toshimasa Futatsugi,Hiroki Oba,Takashi Takizawa,Ryo Munakata,Terue Hatakenaka,Michihiko Koseki,Hiroyuki Kato 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.5

Study Design: Retrospective chart review. Purpose: This study evaluated long-term surgical outcomes of computer-assisted reconstruction using transarticular or cervical pedicle screws for cervical spine lesions caused by advanced rheumatoid arthritis (RA). Overview of Literature: We routinely employ C1–C2 transarticular and cervical pedicle screw instrumentation to reconstruct advanced and unstable RA cervical lesions. However, few reports are available on the long-term results of surgical reconstruction for rheumatoid cervical disorders, particularly regarding cervical pedicle screw fixation. Methods: Six subjects (all female) with RA cervical lesions who underwent atlantoaxial or occipitocervical fixation and were followed for at least 10 years were retrospectively studied. A frameless, stereotactic, optoelectronic, computed tomography-based image guidance system was used for correct screw placement. Variables including the Japanese Orthopaedic Association score, EuroQol, Ranawat value, and C2–C7 angle before and 2, 5, and 10 years after surgery were assessed along with the occurrence of subaxial subluxation (SAS). Results: Mean age at initial surgery was 58.2±7 years (range, 51–68 years), and mean follow-up period was 141±11 months (range, 122–153 months). Lesions included atlantoaxial subluxation (AAS, n=2) and AAS+vertical subluxation (n=4). Mean C2–C7 lordotic angle before and 2, 5, and 10 years after surgery was 20.1°±6.1°, 21.0°±4.0°, 18.8°±4.7°, and 17.8°±5.3°, respectively. SAS did not occur in cases maintaining the C2–C7 lordotic angle. In two cases where the C2–C7 lordotic angle declined from 5 years postoperatively, SAS occurred at the C2–C3 level in one and at the C4–C5 level in the other, both of which required reoperation. Conclusions: Patients with rheumatoid cervical lesions who undergo atlantoaxial or occipitocervical fixation using C1–C2 transarticular or pedicle screws carry a risk of SAS for up to 10 years postoperatively, which may require reoperation.