著者

Naoki IZUTSU Daisuke AKITA Hideyuki FUKE Issei IIJIMA Yoichi KATO Jiro KAWADA Kiyoho MATSUSHIMA Yukihiko MATSUZAKA Eiichi MIZUTA Takashi NAKADA Naoki NONAKA Yoshitaka SAITO Atsushi TAKADA Keisuke TAMURA Kazuhiko YAMADA Tetsuya YOSHIDA

出版者

THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES

雑誌

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN (ISSN:18840485)

巻号頁・発行日

vol.8, no.ists27, pp.Pm_7-Pm_13, 2010 (Released:2010-12-29)

参考文献数

1

被引用文献数

1 1

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A zero-pressure balloon used for scientific observation in the stratosphere has an unmanageable limitation that its floating altitude decreases during a nighttime because of temperature drop of the lifting gas. Since a super-pressure balloon may not change its volume, the lifetime can extend very long. We had introduced so called the ‘lobed-pumpkin’ type of super-pressure balloon that can realize a full-scale long-duration balloon and it will be in practical use in the very near future. As for larger super-pressure balloons, however, we still have some potential difficulties to be resolved. We here propose a new design suitable for a larger super-pressure balloon, which is roughly ‘lobed pumpkin with lobed cylinder’ and can adapt a single design for balloons of a wide range of volumes. Indoor inflation tests were successfully carried out with balloons designed and made by the method. It has been shown that the limit of the resisting pressure differential for a new designed balloon is same as that of a normal lobed-pumpkin balloon.

著者

Atsushi Tateno Masatake Asano Daisuke Akita Taku Toriumi Niina Tsurumachi-Iwasaki Tomohiko Kazama Yoshinori Arai Taro Matsumoto Koichiro Kano Masaki Honda

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0458, (Released:2019-10-21)

参考文献数

45

被引用文献数

13

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Tissue engineering is a promising approach to supplement existing treatment strategies for craniofacial bone regeneration. In this study, a type I collagen scaffold made from a recombinant peptide (RCP) with an Arg-Gly-Asp motif was developed, and its effect on regeneration in critical-size mandibular bone defects was evaluated. Additionally, the combined effect of the scaffold and lipid-free dedifferentiated fat (DFAT) cells was assessed. Briefly, DFAT cells were separated from mature adipocytes by using a ceiling culture technique based on buoyancy. A 3 cm × 4 cm critical-size bone defect was created in the rat mandible, and regeneration was evaluated by using RCP with DFAT cells. Then, cultured DFAT cells and adipose-derived stem cells (ASCs) were seeded onto RCP scaffolds (DFAT/RCP and ASC/RCP) and implanted into the bone defects. Micro-computed tomography imaging at 8 weeks after implantation showed significantly greater bone regeneration in the DFAT/RCP group than in the ASC/RCP and RCP-alone groups. Similarly, histological analysis showed significantly greater bone width in the DFAT/RCP group than in the ASC/RCP and RCP-alone groups. These findings suggest that DFAT/RCP is effective for bone formation in critical-size bone defects and that DFAT cells are a promising source for bone regeneration.

著者

Takahisa Okubo Naoki Tsukimura Takashi Taniyama Manabu Ishijima Kourosh Nakhaei Naser M. Rezaei Makoto Hirota Wonhee Park Daisuke Akita Atsushi Tateno Tomohiko Ishigami Takahiro Ogawa

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.4, pp.567-573, 2018 (Released:2018-12-27)

参考文献数

23

被引用文献数

9

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Titanium mesh plate (Ti mesh) used for bone augmentation inadvertently comes into contact with medical gloves during trimming and bending. We tested the hypotheses that glove contact degrades the biological capability of Ti mesh and that ultraviolet treatment (UV) can restore this capability. Three groups of Ti mesh specimens were prepared: as-received (AR), after glove contact (GC), and after glove contact followed by UV treatment. The AR and GC meshes were hydrophobic, but GC mesh was more hydrophobic. AR and GC meshes had significant amounts of surface carbon, and Si content was higher for GC mesh than for AR mesh. UV mesh was hydrophilic, and carbon and silicon content values were significantly lower in this group than in the AR and GC groups. The number, alkaline phosphatase activity, and mineralization ability of attached osteoblasts were significantly lower in the GC group than in the AR group and markedly higher in the UV group than in the AR group. In conclusion, glove contact caused chemical contamination of Ti mesh, which significantly reduced its bioactivity. UV treatment restored bioactivity in contaminated Ti mesh, which outperformed even the baseline Ti mesh.

著者

Niina Tsurumachi Daisuke Akita Koichiro Kano Taro Matsumoto Taku Toriumi Tomohiko Kazama Yoshinao Oki Yoko Saito-Tamura Morio Tonogi Noriyoshi Shimizu Masaki Honda

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.16-0786, (Released:2018-02-26)

参考文献数

38

被引用文献数

4

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Dedifferentiated fat (DFAT) cells were isolated from mature adipocytes using the ceiling culture method. Recently, we successfully isolated DFAT cells from adipocytes with a relatively small size (<40 μm). DFAT cells have a higher osteogenic potential than that of medium adipocytes. Therefore, the objective of this study was to determine the optimal concentration of collagenase solution for isolating small adipocytes from human buccal fat pads (BFPs). Four concentrations of collagenase solution (0.01%, 0.02%, 0.1%, and 0.5%) were used, and their effectiveness was assessed by the number of small adipocytes and DFAT cells isolated. The total number of floating adipocytes that dissociated with 0.02% collagenase was 2.5 times of that dissociated with 0.1% collagenase. The number of floating adipocytes with a diameter of ≤29 μm that dissociated with 0.02% collagenase was thrice of those dissociated with 0.1% and 0.5% collagenase. The number of DFAT cells that dissociated with 0.02% collagenase was 1.5 times of that dissociated with 0.1% collagenase. In addition, DFAT cells that dissociated with 0.02% collagenase had a higher osteogenic differentiation potential than those that dissociated with 0.1% collagenase. These results suggest that 0.02% is the optimal collagenase concentration for isolating small adipocytes from BFPs.