LOCAL AND NORM BEHAVIOR OF BLOWUP SOLUTIONS TO A PARABOLIC SYSTEM OF CHEMOTAXIS

Senba, Takasi,Suzuki, Takashi Korean Mathematical Society 2000 대한수학회지 Vol.37 No.6

We study a parabolic system of chemotaxis introduced by E.F. Keler and L.A. Segel. First, norm behaviors of the blow-up solution are proven. Then some kind of symmetry breaking and the concentration toward the boundary follow when the L$^1$norm of the initial value is less than 8$\pi$. Meanwhile a method of rearrangement is porposed toprove an inequality of Trudinger-Moser's type.

Characterization of Epitaxial EuS(111) Thin Films on BaF2(111) and SrF2(111) Substrates Grown By Molecular Beam Epitaxy

Shinya Senba,Naoki Matsumoto,Mitsuhiro Jomura,Hironori Asada,Tsuyoshi Koyanagi,Kengo Kishimoto,Yasuhiro Fukuma 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12

We have successfully grown EuS (111) epitaxial films on BaF2 (111) and SrF2 (111) substratesby using molecular beam epitaxy at substrate temperatures (TS’s) between 100 and 500 C. Polefigures of X-ray diffraction indicate a high degree of in-plane orientation, and all of the samplesshowvery high resistivity. The surface roughness for 10-nm-thick EuS films on BaF2 (111) and SrF2 (111)substrates measured by using atomic force microscopy (AFM) are 0.122 and 0.092 nm, respectively. The Curie temperature of the EuS films increases up to 16 K with increasing TS. We also try tomanipulate the coercive force, which is an important magnetic property, by Te-doping to achieve ananti-parallel magnetization state between two ferromagnetic layers in spin devices. The obtainedcoercive force for the Te-doped film (110 Oe) is large compared with that for the undoped one (20Oe).

Sensitivity analysis of thermal deformation of CFRP laminate reflector due to fiber orientation error

Shun Tanaka,Tadashige Ikeda,Atsuhiko Senba 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.10

Carbon fiber reinforced plastic (CFRP) laminates are sometimes adopted as material of space observation systems because their specific stiffness is high and thermal deformation can be controlled by stacking sequence and fiber orientation. However, unexpected out-ofplane thermal deformation is generated on CFRP laminate plates because of fiber orientation error. In this research, a CFRP reflector model was built and its thermal deformation was measured to determine the kinds of deformation generated on the reflector. In the experiment, non-axisymmetric deformation was generated even for uniform heating. Finite-element analysis (FEA) on thermal deformation of the reflector model was performed to explain non-axisymmetric deformation. FEA showed that non-axisymmetric deformation was generated by fiber orientation error. The thermal deformation of the CFRP reflector model was strongly affected by fiber orientation error, and accordingly, the fiber orientation angle of CFRP reflectors should be controlled strictly depending on the desired accuracy.

Cervical Myelopathy Caused by Disc Herniation at the Segment of Existing Osteochondroma in a Patient with Hereditary Multiple Exostoses

Ko Ikuta,Kiyoshi Tarukado,Hideyuki Senba,Takahiro Kitamura,Norihiro Komiya,Satoshi Shidahara 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6

Hereditary multiple exostoses (HME) is a benign hereditary disorder characterized by multiple osteochondromas. Osteochondroma appears occasionally in the spinal column as a part of HME. A 37-year-old man presented with a history of HME and cervical compressive myelopathy caused by intraspinal osteochondroma arising from the lamina of the C5 and disc herniation at the C5–6. He was treated by open-door laminoplasty at the C5 and C6 with excision of the tumor. The neurological symptoms were immediately relieved after surgery. Magnetic resonance images demonstrated a sufficient decompression of the spinal cord with a spontaneous regression of the herniated disc at one year after surgery. There was no recurrence of the tumor and no appearance of kyphosis and segmental instability of the cervical spine on postoperative imaging studies for three years after surgery. The patient could be successfully treated by laminoplasty with excision of the tumor and without removal of the herniated disc.

Possible involvement of food texture in insulin resistance and energy metabolism in male rats

Bae, Cho-Rong,Hasegawa, Kazuya,Akieda-Asai, Sayaka,Kawasaki, Yurie,Senba, Kazuyo,Cha, Youn-Soo,Date, Yukari Society for Endocrinology 2014 The Journal of endocrinology Vol.222 No.1

<P>Food texture is known to affect energy metabolism. Although feeding with soft pellets (SP) or via a tube is known to cause increases in body weight, it is unclear how different food textures influence energy metabolism. In this study, we investigated the effects of two different food textures on energy balance and glucose and lipid metabolism in male Wistar rats. The rats were fed SP or control pellets (CP) on a 3-h restricted feeding schedule for 14 weeks and their energy intake, body weight, and energy expenditure were examined. The levels of gastrointestinal hormones, glucose and insulin, were investigated at pre-, mid, and post-feeding. Glucose tolerance and insulin tolerance tests were conducted, and the expressions of molecules involved in the insulin signaling system or lipogenesis in the liver were examined. Histological investigation of pancreatic islets was carried out using anti-insulin and anti-Ki-67 antibodies. Furthermore, the expression in the liver and circulating blood of microRNA-33 (miR-33), which regulates insulin receptor substance 2, was examined. There were no significant differences in energy intake, body weight, or gastrointestinal hormone levels between the SP and CP rats; however, the SP rats showed glucose intolerance and insulin resistance with disruption of insulin signaling. Increases in lipogenic factors and miR-33 expression were also found in the SP rats. The numbers of insulin-positive areas and Ki-67-positive cells of SP rats were significantly increased. This study shows that a soft food texture causes diabetes without obesity, so differences in food texture may be an important factor in type 2 diabetes.</P>

Surgical Outcomes of Minimally Invasive Stabilization for Spinal Fractures in Patients with Ankylosing Spinal Disorders

Kazuhiro Kai,Ko Ikuta,Keigo Masuda,Takahiro Kitamura,Hideyuki Senba,Satoshi Shidahara 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.3

Study Design: A retrospective study. Purpose: To evaluate the clinical and radiological outcomes of ankylosing spinal disorder (ASD) patients with spinal fractures treated by minimally invasive stabilization (MISt) using percutaneous pedicle screws (PPSs). Overview of Literature: ASDs, such as ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), increase susceptibility to spinal fractures because of extremely decreased spinal flexibility. Such fractures tend to be unstable and, consequently, should be treated with multiple-segmental internal fixation. However, conventional internal fixation procedures can severely damage the soft tissue, resulting in severe hemorrhage. Therefore, MISt is the preferred approach to treat spinal fractures in ASD patients. Methods: Nine ASD patients (four males and five females; three AS and six DISH patients) with spinal fractures who were treated by MISt using PPSs, were reviewed from April 2009 to August 2016. One patient died of aspiration pneumonia during follow-up (FU), and the remaining eight patients underwent clinical and radiological evaluation. Results: The mean age at surgery was 79.6 years (range, 68–95 years). The mean duration of postoperative FU was 14.2 months (range, 3–30 months). All treated fractures were anterior and posterior element injuries with distraction. Three patients presented delayed onset preoperative neurological deficit following trauma. The mean operation time was 179.6 minutes (range, 92–340 minutes). The mean hemorrhage was 103.6 mL (range, unquantifiable to 480 mL). Radiological evaluations at FU showed preservation of the acceptable postoperative correction of the fractured vertebra, as there were no re-collapses of the fractured vertebrae during FU. Conclusions: ASD patients must be acknowledged as highly susceptible to unstable spinal fractures, even after relatively mild trauma. MISt using PPSs may be an effective treatment for spinal fractures in such patients.

Percutaneous Transpedicular Interbody Fusion Technique in Percutaneous Pedicle Screw Stabilization for Pseudoarthrosis Following Pyogenic Spondylitis

Ko Ikuta,Keigo Masuda,Yutaka Yonekura,Takahiro Kitamura,Hideyuki Senba,Satoshi Shidahara 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.2

This report introduces a percutaneous transpedicular interbody fusion (PTPIF) technique in posterior stabilization using percutaneous pedicle screws (PPSs). An 81-year-old man presented with pseudoarthrosis following pyogenic spondylitis 15 months before. Although no relapse of infection was found, he complained of obstinate low back pain and mild neurological symptoms. Radiological evaluations showed a pseudoarthrosis following pyogenic spondylitis at T11–12. Posterior stabilization using PPSs from Th9 to L2 and concomitant PTPIF using autologous iliac bone graft at T11–12 were performed. Low back pain and neurological symptoms were immediately improved after surgery. A solid interbody fusion at T11–12 was completed 9 months after surgery. The patient had no restriction of daily activity and could play golf at one year after surgery. PTPIF might be a useful option for perform segmental fusion in posterior stabilization using PPSs.

Minimally Invasive Transtubular Endoscopic Decompression for L5 Radiculopathy Induced by Lumbosacral Extraforaminal Lesions

Ko Ikuta,Takahiro Kitamura,Keigo Masuda,Kensuke Hotta,Hideyuki Senba,Satoshi Shidahara 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.2

Study Design: Retrospective study. Purpose: This study aimed to evaluate the efficacy of minimally invasive transtubular endoscopic decompression for the treatment of lumbosacral extraforaminal lesion (LSEFL). Overview of Literature: Conventional procedures for surgical decompression for the treatment of LSEFL involve certain technical challenges because the lumbosacral extraforaminal region has unique anatomical features. Moreover, the efficacy of minimally invasive procedures performed via the posterolateral approach for LSEFL has been reported. Methods: Twenty-five patients who had undergone minimally invasive transtubular endoscopic decompression for the treatment of LSEFL and could be followed up for at least 1 year postoperatively were enrolled. Five of these patients had a history of lumbar surgery, and seven had concomitant adjacent-level spinal stenosis. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) lumbar score, numeric rating scale (NRS), and the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The mean postoperative follow-up (FU) duration was 3.8 years. Results: All procedures could be completed without any severe surgical complications, and all patients could resume their previous activity level within 1 month postoperatively. The JOA score significantly increased from 14.1±4.0 at baseline to 23.1±3.7 at the 1-year FU and 22.1±3.8 at the last FU. Similarly, there were significant improvements in the postoperative NRS and JOABPEQ scores. An additional surgery was performed in two patients (8%) during the FU period. Patients with degenerative scoliosis exhibited significantly poorer outcomes compared with those without this condition. Conclusions: Transtubular endoscopic decompression can overcome certain technical challenges involved in the conventional procedures for LSEFL treatment; therefore, it can be recommended as a useful procedure for treating LSEFL. This procedure can provide some benefits to LSEFL patients and offer a well-illuminated surgical field and high surgical safety for the surgeon. However, the procedure should be carefully adapted for LSEFL patients with concomitant degenerative scoliosis.

Risk Factor Analysis for C5 Palsy after Double-Door Laminoplasty for Cervical Spondylotic Myelopathy

Satoshi Baba,Ko Ikuta,Hiroko Ikeuchi,Makoto Shiraki,Norihiro Komiya,Takahiro Kitamura,Hideyuki Senba,Satoshi Shidahara 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.2

Study Design: A retrospective comparative study. Purpose: To clarify the risk factors related to the development of postoperative C5 palsy through radiological studies after cervical double-door laminoplasty (DDL). Overview of Literature: Although postoperative C5 palsy is generally considered to be the result of damage to the nerve root or segmental spinal cord, the associated pathology remains controversial. Methods: A consecutive case series of 47 patients with cervical spondylotic myelopathy treated by DDL at our institution between April 2008 and April 2015 were reviewed. Postoperative C5 palsy occurred in 5 of 47 cases after DDL. We investigated 9 radiologic factors that have been reported to be risk factors for C5 palsy in various studies, and statistically examined these between the two groups of palsy and the non-palsy patients. Results: We found a significant difference between patients with and without postoperative C5 palsy with regards to the posterior shift of spinal cord at C4/5 (p =0.008). The logistic regression analyses revealed posterior shift of the spinal cord at C4/5 (odds ratio, 12.066; p =0.029; 95% confidence interval, 1.295–112.378). For the other radiologic factors, there were no statistically significant differences between the two groups. Conclusions: In the present study, we showed a significant difference in the posterior shift of the spinal cord at C4/5 between the palsy and the non-palsy groups, indicating that the “tethering phenomenon” was likely a greater risk factor for postoperative C5 palsy.

Technique for transvaginal removal of large specimen using an Alexis Contained Extraction System during laparoscopic hysterectomy

Iori Kisu,Kouji Banno,Asahi Tokuoka,Keigo Yamaguchi,Kunio Tanaka,Tetsuro Shiraishi,Kanako Nakamura,Hiroshi Senba,Kiyoko Matsuda,Nobumaru Hirao 대한산부인과학회 2022 Obstetrics & Gynecology Science Vol.65 No.3

ObjectiveTransvaginal removal of large specimens during laparoscopic hysterectomy can be a complex surgical procedure thatposes a risk of organ injury and tissue spillage into the abdominal cavity and is associated with extraction of thespecimen and manual morcellation. Our objective was to demonstrate a technique for transvaginal removal of largespecimens using the Alexis Contained Extraction System (CES) in laparoscopic hysterectomy. MethodsThe technique used for transvaginal removal of large specimens using the Alexis CES was presented in this video. Surgery was performed at a tertiary hospital. ResultsFollowing resection of the specimen during laparoscopic hysterectomy, the Alexis CES was inserted into the abdominalcavity through the umbilical trocar wound. The specimen was placed in a bag to prevent tissue spillage. The ringretractor was guided to the vagina and pulled out transvaginally. By repeatedly turning the ring retractor, tensionwas applied to the specimen bag, and the vaginal wall was unfolded all around to enable a secure surgical field. During manual morcellation of the specimen in the bag, the retractor was pulled and additionally turned to roll andre-tension the specimen bag when the bag was loosened. The specimen was pushed out of the vagina and safely andeffectively extracted without concerns about tissue spillage in the abdominal cavity or related organ injuries. ConclusionThe technique for transvaginal removal of large specimens using the Alexis CES enables simple, effective, and safetissue extraction with contained manual morcellation during laparoscopic hysterectomy. 영어