402 results on '"Yasuhiko, Hayashi"'
Search Results
2. Administration of glucocorticoids prior to liquid biopsy dramatically reduces the detection rate of MYD88 L265P mutation in cerebrospinal fluid of primary CNS lymphoma patients
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Haruhiko Takahashi, Manabu Natsumeda, Jotaro On, Jun Watanabe, Mari Tada, Hiroshi Shimizu, Yoshihiro Tsukamoto, Masayasu Okada, Makoto Oishi, Jun Takizawa, Yasuhiko Hayashi, Yasufumi Masaki, Akiyoshi Kakita, and Yukihiko Fujii
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Cancer Research ,Oncology ,Hematology - Published
- 2023
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3. Integration of Wireless Power Transfer Technology With Hierarchical Multiwalled Carbon Nanotubes-Polydimethylsiloxane Piezo-Responsive Pressure Sensor for Remote Force Measurement
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Saman Azhari, Kouki Kimizuka, Gábor Méhes, Yuki Usami, Yasuhiko Hayashi, Hirofumi Tanaka, and Takeo Miyake
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Electrical and Electronic Engineering ,Instrumentation - Published
- 2023
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4. Significant Correlates of Nocturnal Hypertension in Patients With Hypertension Who Are Treated With Antihypertensive Drugs
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Tatsuya Maruhashi, Yoshihiko Kinoshita, Ryoji Ozono, Mitsuaki Nakamaru, Masanori Ninomiya, Jiro Oiwa, Takuji Kawagoe, Osamu Yoshida, Toshiyuki Matsumoto, Yasuo Fukunaga, Kotaro Sumii, Hironori Ueda, Nobuo Shiode, Kosuke Takahari, Yasuhiko Hayashi, Yujiro Ono, Yukiko Nakano, Masakazu Takahashi, Yasuki Kihara, and Yukihito Higashi
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Internal Medicine - Abstract
Background Nocturnal hypertension assessed by a home blood pressure monitoring (HBPM) device is associated with an increased risk of cardiovascular events. However, it is still difficult to assess nighttime blood pressure (BP) frequently. The purpose of this cross-sectional study was to identify significant correlates of nocturnal hypertension assessed by an HBPM device in patients with hypertension who are treated with antihypertensive drugs. Methods We measured nighttime BP, morning BP, and evening BP by an HBPM device for 7 consecutive days in 365 medicated patients with hypertension. Results Of the 365 subjects, 138 (37.8%) had nocturnal hypertension defined as a mean nighttime systolic BP of ≥ 120 mm Hg. Receiver operating characteristic curve analyses showed that the diagnostic accuracy of morning systolic BP for subjects with nocturnal hypertension was significantly superior to that of evening systolic BP (P = 0.04) and that of office systolic BP (P Conclusions Morning systolic BP of ≥ 125 mm Hg, a history of cerebrovascular disease, and bedtime dosing were significant correlates of nocturnal hypertension in medicated patients with hypertension, and may help detect this risky BP condition. Clinical trials registration University Hospital Medical Information Network Clinical Trials Registry (UMIN000019173).
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- 2023
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5. Characteristics of Vertical Ga2O3 Schottky Junctions with the Interfacial Hexagonal Boron Nitride Film
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Venkata Krishna Rao Rama, Ajinkya K. Ranade, Pradeep Desai, Bhagyashri Todankar, Golap Kalita, Hiroo Suzuki, Masaki Tanemura, and Yasuhiko Hayashi
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General Chemical Engineering ,General Chemistry - Abstract
We present the device properties of a nickel (Ni)- gallium oxide (Ga2O3) Schottky junction with an interfacial hexagonal boron nitride (hBN) layer. A vertical Schottky junction with the configuration Ni/hBN/Ga2O3/In was created using a chemical vapor-deposited hBN film on a Ga(2)O(3 )substrate. The current-voltage characteristics of the Schottky junction were investigated with and without the hBN interfacial layer. We observed that the turn-on voltage for the forward current of the Schottky junction was significantly enhanced with the hBN interfacial film. Furthermore, the Schottky junction was analyzed under the illumination of deep ultraviolet light (254 nm), obtaining a photoresponsivity of 95.11 mA/W under an applied bias voltage (-7.2 V). The hBN interfacial layer for the Ga2O3-based Schottky junction can serve as a barrier layer to control the turn-on voltage and optimize the device properties for deep-UV photosensor applications. Furthermore, the demonstrated vertical heterojunction with an hBN layer has the potential to be significant for temperature management at the junction interface to develop reliable Ga2O3-based Schottky junction devices.
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- 2022
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6. Progression from paroxysmal to persistent atrial fibrillation in pacemaker patients with tachycardia–bradycardia syndrome: a multicenter study
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Naoto Oguri, Akinori Sairaku, Nobuyuki Morishima, Yasuhiko Hayashi, Yuji Muraoka, Shunsuke Tomomori, Takenori Okada, and Yukiko Nakano
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Cardiology and Cardiovascular Medicine - Published
- 2023
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7. Highly Oriented Carbon Nanotube Supercapacitors
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Kohei Komatsubara, Hiroo Suzuki, Hirotaka Inoue, Misaki Kishibuchi, Shona Takahashi, Tatsuki Marui, Shigeyuki Umezawa, Tomohiro Nakagawa, Kyohei Nasu, Mitsuaki Maetani, Yuichiro Tanaka, Miyato Yamada, Takeshi Nishikawa, Yoshifumi Yamashita, Masaki Hada, and Yasuhiko Hayashi
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General Materials Science - Published
- 2022
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8. Challenges for developing photo-induced phase transition (PIPT) systems: From classical (incoherent) to quantum (coherent) control of PIPT dynamics
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Tadahiko Ishikawa, Yoichi Okimoto, Ken Onda, Ryo Fukaya, Sumio Ishihara, Tadeusz Luty, Yasuhiko Hayashi, Shin-ya Koshihara, and Masaki Hada
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Physics ,Phase transition ,Field (physics) ,Coherent control ,General Physics and Astronomy ,Electron ,Ground state ,Ultrashort pulse ,Quantum ,Engineering physics ,Light field - Abstract
This work reviews the experimental studies on photo-induced cooperative phenomena (photo-induced phase transitions, PIPT), which are related to ultrafast structural and electronic-state dynamics. The review includes a brief history of this research field. The current growth of PIPT research is facilitated by deep collaboration between quantum beam science and materials science. Meanwhile, owing to developments in ultrafast quantum beam technology, the concept of PIPT itself has largely expanded. In the initial stage of PIPT research, the dynamical PIPT process was thought to be governed by energy relaxation from the photoexcited state, which is a classical and incoherent process. Therefore, the main research target was realizing the quasi-stable state on the energy surface of the ground state. Using ultrashort pulsed light and quantum beam technologies (including X-ray and electron technologies), one can now directly probe the ultrafast and coherent electronic dynamics of PIPT materials coupled with changes in their structural properties. This new technology has realized a new ordered phase called the hidden state, which is unique to the photoexcited state. Modern laser technology has also enabled a controlled PIPT process utilizing coherent coupling between the light field and electronic states in materials. Exploiting these leaps in experimental techniques, we have expanded the way of controlling PIPT dynamics from classical (incoherent) to coherent/quantum processes. This review discusses the recent developments in PIPT tuning via quantum (coherent) control methods based on charge–lattice (orbital)–spin coupled materials.
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- 2022
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9. Copper-incorporation for polytypism and bandgap engineering of MAPbBr3 perovskite thin films with enhanced near-Infrared photocurrent-response
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Amr Elattar, Jiban Kangsabanik, Kodai Nakao, Kosei Tsutsumi, Hiroo Suzuki, Takeshi Nishikawa, Kristian S. Thygesen, and Yasuhiko Hayashi
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Materials Chemistry ,General Materials Science - Abstract
Formation of secondary phase polytypes through incorporation of copper into MAPbBr3 perovskite yields bandgap reduction with generation of near-IR photocarriers.
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- 2022
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10. Structure modulation for bandgap engineered vacancy-ordered Cs3Bi2Br9 perovskite structures through copper alloying
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Amr Elattar, Libor Kobera, Jiban Kangsabanik, Hiroo Suzuki, Sabina Abbrent, Takeshi Nishikawa, Kristian S. Thygesen, Jiri Brus, and Yasuhiko Hayashi
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Materials Chemistry ,General Chemistry - Abstract
Light absorption enhancement was achieved through structure modulation of the Cs3Bi2Br9 perovskite crystal via Cu-alloying. The Cs3Bi2Br9 perovskite retains its matrix structure with homogeneously distributed Cs2CuBr4 large domains.
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- 2022
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11. Mixed-halide copper-based perovskite R2Cu(Cl/Br)4 with different organic cations for reversible thermochromism
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Amr Elattar, Kosei Tsutsumi, Hiroo Suzuki, Takeshi Nishikawa, Aung Ko Ko Kyaw, and Yasuhiko Hayashi
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Materials Chemistry ,General Chemistry ,Catalysis - Abstract
Mechanically exfoliated flakes of mixed-halide Cu-based perovskite crystals, R2Cu(Cl/Br)4, with three alkyl chains exhibit reversible thermochromic behavior with differences in crystal lattice behavior depending on the organic spacer used.
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- 2022
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12. Supercapacitor electrode with high charge density based on boron-doped porous carbon derived from covalent organic frameworks
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Daisuke Tanaka, Koji Yoshikawa, Vlad Stolojan, S. Ravi P. Silva, Shigeyuki Umezawa, Yasuhiko Hayashi, Takashi Douura, Mika Yoneda, Yohei Takashima, and Kazuma Gotoh
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Supercapacitor ,Materials science ,Carbonization ,chemistry.chemical_element ,General Chemistry ,Capacitance ,chemistry ,Chemical engineering ,Electrode ,medicine ,General Materials Science ,Boron ,Carbon ,Covalent organic framework ,Activated carbon ,medicine.drug - Abstract
We developed a facile and unique process for preparing boron-doped porous carbon by direct carbonization of a boron-based covalent organic framework (COF-5). Boron oxides, which are formed during the carbonization of COF-5, were readily removed through water treatment of the resulting carbon to obtain boron-doped porous carbon. Thus, boron atoms were successfully incorporated into the carbon matrix. Supercapacitor electrodes made of the fabricated boron-doped carbon exhibited a specific capacitance of 15.3 μF cm−2 at 40 mA g−1, which is twice that of the conventional activated carbon electrode (∼6.9 μF cm−2) at the same current density, owing to the presence of boron atoms in the carbon material. The supercapacitors based on boron-doped carbon demonstrated 72% capacitance retention after 10000 charge/discharge cycles. The boron-doped COF-derived carbon materials can serve as a new class of multifunctional carbon materials for energy storage devices.
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- 2021
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13. Memristive Behavior in One-Dimensional Hexagonal Boron Nitride/Carbon Nanotube Heterostructure Assemblies
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Mitsuaki Maetani, Kyohei Nasu, Yuichiro Tanaka, Hiroo Suzuki, Hirotaka Inoue, Misaki Kishibuchi, Kazuma Shimogami, Yasuhiko Hayashi, and Tomohiro Nakagawa
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Materials science ,business.industry ,Hexagonal boron nitride ,Heterojunction ,Carbon nanotube ,Memristor ,Electronic, Optical and Magnetic Materials ,law.invention ,Non-volatile memory ,Neuromorphic engineering ,law ,Materials Chemistry ,Electrochemistry ,Optoelectronics ,business - Published
- 2021
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14. Characteristics of Vertical Ga
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Venkata Krishna Rao, Rama, Ajinkya K, Ranade, Pradeep, Desai, Bhagyashri, Todankar, Golap, Kalita, Hiroo, Suzuki, Masaki, Tanemura, and Yasuhiko, Hayashi
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We present the device properties of a nickel (Ni)-gallium oxide (Ga
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- 2022
15. Surface Diffusion-Limited Growth of Large and High-Quality Monolayer Transition Metal Dichalcogenides in Confined Space of Microreactor
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Hiroo Suzuki, Ryoki Hashimoto, Masaaki Misawa, Yijun Liu, Misaki Kishibuchi, Kentaro Ishimura, Kenji Tsuruta, Yasumitsu Miyata, and Yasuhiko Hayashi
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General Engineering ,General Physics and Astronomy ,General Materials Science - Abstract
Transition metal dichalcogenides (TMDCs), including MoS
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- 2022
16. Thyrotropin-secreting pituitary adenomas induce left atrial enlargement with subclinical atrial fibrillation: an echocardiographic study
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Kenji Yoshiki, Masaya Shimojima, Mitsutoshi Nakada, Sho Takata, Yasuhiko Hayashi, Osamu Tachibana, Yumie Takeshita, Yasuo Sasagawa, and Toshinari Takamura
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Cardiac function curve ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Thyrotropin ,030209 endocrinology & metabolism ,Ventricular Function, Left ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Pituitary adenoma ,Diabetes mellitus ,Internal medicine ,Atrial Fibrillation ,Left atrial enlargement ,Humans ,Medicine ,Pituitary Neoplasms ,Subclinical infection ,Ejection fraction ,business.industry ,Thyroid ,Stroke Volume ,Atrial fibrillation ,medicine.disease ,medicine.anatomical_structure ,Echocardiography ,cardiovascular system ,Cardiology ,business ,030217 neurology & neurosurgery - Abstract
Thyrotropin-secreting pituitary adenoma (TSHoma) is rare but occasionally causes cardiovascular complications such as atrial fibrillation (AF) due to hyperthyroidism. Graves' disease (GD) is a common hyperthyroid condition often associated with subclinical AF. Some reports have shown echocardiographic changes in patients with GD. We aimed to evaluate the preoperative cardiac function in patients with TSHomas and compared the results among patients with TSHomas and GD and control subjects. Patients with TSHomas (n = 6) and GD (n = 20) were compared with control subjects with normal cardiac function (n = 20) based on echocardiographic findings. The average age, sex, and proportions of patients with a history of diabetes mellitus and hypertension were equal in each group, and the AF prevalence was matched in patients with TSHomas and GD. The values of left ventricular end-diastolic diameter (LVEDd), left ventricular end-systolic diameter (LVEDs), left ventricular ejection fraction (LVEF), and left atrial diameter (LAD) were used to assess cardiac function. In echocardiography, LAD showed a significant difference between patients with TSHomas and control subjects (p = 0.026). The mean LAD values were 36.9 ± 7.1, 38.2 ± 8.9, and 28.7 ± 3.9 mm for patients with TSHomas and GD and control subjects, respectively. There were no significant differences in other echocardiographic parameters among the groups. Before treatment, serum thyroid hormone levels (free triiodothyronine and thyroxin) were not significantly different among patients with TSHomas and GD. We found that patients with TSHomas or GD had enlarged LADs. This finding suggests that AF may be more hidden in patients with TSHomas than previously reported.
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- 2021
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17. A case of rapid deterioration in a subacute period after endoscopic third ventriculostomy
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Mitsutoshi Nakada, Toshiya Ichinose, Ryo Higashi, Yasuo Sasagawa, Yasuhiko Hayashi, and Masahiro Oishi
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medicine.medical_specialty ,business.industry ,Endoscopic third ventriculostomy ,General Medicine ,medicine.disease ,Third ventriculostomy ,Surgery ,Hydrocephalus ,03 medical and health sciences ,0302 clinical medicine ,Neuroendoscopy ,030220 oncology & carcinogenesis ,medicine ,Neurology (clinical) ,business ,Complication ,030217 neurology & neurosurgery - Abstract
Background: Although generally a safe procedure, serious postoperative complications after endoscopic third ventriculostomy (ETV) for obstructive hydrocephaly have been rarely reported, such as del...
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- 2021
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18. The Process of Thinking about How to Create Scientific Articles
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Yasuhiko Hayashi
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Surgery ,Neurology (clinical) - Published
- 2021
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19. Nanostructural characterization of carbon nanotube yarn high-strengthened by joule heating
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Hirotaka Inoue, Takaya Tezuka, Toru Kuzumaki, Norio Mori, Tomohiro Nakagawa, Takuya Murayama, Takuma Sano, and Yasuhiko Hayashi
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Materials science ,Modulus ,02 engineering and technology ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Characterization (materials science) ,Crystallinity ,law ,Ultimate tensile strength ,General Materials Science ,Composite material ,0210 nano-technology ,Carbon nanotube yarn ,Joule heating ,Spinning - Abstract
The high-strengthening mechanism of carbon nanotube (CNT) yarns subjected to Joule heating was investigated by nanostructural characterization. CNT yarns produced at two drawing speeds (40 and 120 mm/min) with a spindle rotation of 1000 min−1 were used. The mechanical properties of the CNT yarns were improved by Joule heating under a vacuum of 10−6 Pa. The mean tensile strength and Young’s modulus of both yarns heated at 2273 K were approximately 1.1–1.4 GPa and 44–50 GPa, respectively; these values are approximately more than two times those of the as-spun samples. The high-strengthening of the Joule-heated CNT yarns is attributed to the synergistic effect of structural changes such as improvement in the crystallinity of the CNTs, formation of the bundle structure of individual CNTs possessing a polygonal structure, and entwining of these bundles. Meanwhile, the samples in which the high-strengthening mechanism by Joule heating did not initiate, were included in the CNT yarns produced at a drawing speed of 40 mm/min. Cross-sectional observation of the lower-strength CNT yarns revealed the presence of numerous voids in the outer portion of the yarn. The structural defects formed during the spinning of the CNT yarn strongly affected the tensile strength of the yarn.
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- 2021
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20. Zinc‐Based Metal–Organic Frameworks for High‐Performance Supercapacitor Electrodes: Mechanism Underlying Pore Generation
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Shigeyuki Umezawa, Takashi Douura, Koji Yoshikawa, Daisuke Tanaka, Vlad Stolojan, S. Ravi P. Silva, Mika Yoneda, Kazuma Gotoh, and Yasuhiko Hayashi
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Renewable Energy, Sustainability and the Environment ,General Materials Science ,Environmental Science (miscellaneous) ,Waste Management and Disposal ,Energy (miscellaneous) ,Water Science and Technology - Published
- 2022
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21. [Locations and Functions of Water Selective Channels from the View-Points of Cerebrospinal Fluid Distribution]
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Yasuhiko, Hayashi
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Choroid Plexus ,Humans ,Water ,Aquaporins ,Cerebral Ventricles ,Cerebrospinal Fluid ,Hydrocephalus - Abstract
Water not only exists in the ventricles and cisterns but is also contained in the cerebral parenchyma. Water movement in most tissues has been described to be mediated by water channels since the discovery of these channels(aquaporins: AQPs). As to the intracranial situation, AQP-1 is abundantly expressed in the epithelial cells of the choroid plexus. AQP-4 is also enriched in the ependyma, endfeet of astrocytes at the blood-brain barrier, and glia limitans. AQP-4 is involved in cerebrospinal fluid(CSF)absorption, while AQP-1 is involved in CSF production. Impairment of CSF absorption through AQP-4 is considered to be caused by an inflammatory mechanism and finally leads to the development of hydrocephalus. Recently, the glymphatic system was recognized as an intracranial lymphatic system and hypothesized to be involved in CSF absorption and waste removal into the CSF. Disturbances of this glymphatic system may induce Alzheimer's disease and idiopathic normal-pressure hydrocephalus. Although the mechanism of CSF production in the epithelial cells of the choroid plexus remains to be elucidated, the existence of glycolysis leading to the facilitation of AQP-1 expression is considered a key point in CSF production.
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- 2022
22. Phonon transport probed at carbon nanotube yarn/sheet boundaries by ultrafast structural dynamics
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Yoshifumi Yamashita, S. Ravi P. Silva, Taisuke Hasegawa, Muneaki Hase, Masaki Hada, Hiroo Suzuki, Hirotaka Inoue, Jun-ichi Fujita, Jiro Matsuo, Shin-ya Koshihara, Satoshi Maeda, Takeshi Nishikawa, Kotaro Makino, Yasuhiko Hayashi, Hideki Masuda, Tomohiro Nakagawa, Keiichi Shirasu, Vlad Stolojan, and Toshio Seki
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Materials science ,Phonon ,Annealing (metallurgy) ,Graphene ,Thermodynamic equilibrium ,Ultrafast electron diffraction ,02 engineering and technology ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Condensed Matter::Materials Science ,Electron diffraction ,Chemical physics ,law ,Thermal ,General Materials Science ,0210 nano-technology - Abstract
Modern integrated devices and electrical circuits have often been designed with carbon nanostructures, such as carbon nanotubes (CNTs) and graphene due to their high thermal and electrical transport properties. These transport properties are strongly correlated to their acoustic phonon and carrier dynamics. Thus, understanding the phonon and carrier dynamics of carbon nanostructures in extremely small regions will lead to their further practical applications. Here, we demonstrate ultrafast time-resolved electron diffraction and ultrafast transient spectroscopy to characterize the phonon and carrier dynamics at the boundary of quasi-one-dimensional CNTs before and after Joule annealing. The results from ultrafast time-resolved electron diffraction show that the CNTs after Joule annealing reach the phonon equilibrium state extremely fast with a timescale of 10 ps, which indicates that thermal transport in CNTs improves following Joule annealing. The methodology described in this study connects conventional macroscopic thermo- and electrodynamics to those at the nanometer scale. Realistic timescale kinetic simulations were performed to further elaborate on the phenomena that occur in CNTs during Joule annealing. The insights obtained in this study are expected to pave the way to parameterize the unexplored thermal and electrical properties of carbon materials at the nanometer scale.
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- 2020
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23. Aquaporin 1 elicits cell motility and coordinates vascular bed formation by downregulating thrombospondin type‐1 domain‐containing 7A in glioblastoma
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Seiichi Munesue, Masahiro Oishi, Yasuhiko Yamamoto, Yasuhiko Hayashi, Ai Harashima, and Mitsutoshi Nakada
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Male ,0301 basic medicine ,Cancer Research ,Apoptosis ,tube formation ,urologic and male genital diseases ,0302 clinical medicine ,Cell Movement ,Tumor Cells, Cultured ,Original Research ,Cancer Biology ,Aged, 80 and over ,Tube formation ,Neovascularization, Pathologic ,Chemistry ,Cell migration ,Middle Aged ,Prognosis ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Gene Expression Regulation, Neoplastic ,Survival Rate ,Oncology ,030220 oncology & carcinogenesis ,Aquaporin 1 ,aquaporin‐1 ,Female ,Adult ,Down-Regulation ,lcsh:RC254-282 ,Focal adhesion ,03 medical and health sciences ,Downregulation and upregulation ,Glioma ,vascular bed ,Biomarkers, Tumor ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Cell Proliferation ,Thrombospondin ,urogenital system ,glioblastoma ,medicine.disease ,nervous system diseases ,030104 developmental biology ,THSD7A ,Cell culture ,Cancer research ,Thrombospondins - Abstract
Background Aquaporin (AQP) 1 expression has been linked with tumor malignancy but its role in glioblastoma (GBM), a lethal glioma, remains to be clarified. Methods AQP1 expression was examined in 33 human GBM specimens by immunohistochemistry. GBM cells (U251 and U87) that stably express AQP1 were established and used for cellular proliferation, migration, invasion, and vascular tube formation assays. The GeneChip assay was used to identify differentially expressed genes in AQP1‐expressing cells. Results AQP1 was expressed only in tumor cells. AQP1 dose‐dependently accelerated cell migration and invasion, but not proliferation, in GBM cell lines. AQP1 also upregulated cathepsin B, focal adhesion kinase and activities of matrix metalloproteinase 9. AQP1 in GBM cells induced wall thickness of ECV304, vascular endothelial cells, in a contact‐dependent manner. Downregulation of thrombospondin type 1 domain containing 7A (THSD7A) was identified in AQP1‐expressing GBM cells in vitro, and was negatively correlated with AQP1 expression in human GBM specimens. Conclusion AQP1 is involved in tumor malignancy by facilitating the migration and invasion of GBM cells, and promoting the formation of vascular beds that are characteristic of GBM by downregulating THSD7A., We examined whether AQP1 could enhance the malignant properties of GBM in vitro, including cell proliferation, migration, invasion, and blood vessel‐like tube formation. AQP1 is involved in tumor malignancy by facilitating the migration and invasion of GBM cells, and promoting the formation of vascular beds that are characteristic of GBM by downregulating THSD7A.
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- 2020
24. Progressively Enlarged Convexity Arachnoid Cysts in Elderly Patients: A Report of 2 Cases
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Masahiro Oishi, Yasuhiko Hayashi, Ryouken Kimura, Masashi Kinoshita, Masaaki Kobayashi, Mitsutoshi Nakada, and Yasuo Sasagawa
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,medicine.disease ,Shunt (medical) ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Cerebrospinal fluid ,Ventricle ,030220 oncology & carcinogenesis ,Memory disturbance ,medicine ,Surgery ,Cyst ,Arachnoid Membrane ,Neurology (clinical) ,Radiology ,Subdural space ,business ,030217 neurology & neurosurgery - Abstract
Background Generally, enlargement of arachnoid cysts (ACs) has been found mostly in cases occurring during early childhood. Therefore, progressively enlarged ACs found to be symptomatic in elderly patients are extremely rare, and the mechanisms have remained unexplored. Case Description Our first patient was a 72-year-old woman with memory disturbance, who had presented with a large cyst beneath the right temporal convexity 9 years previously. The annual follow-up magnetic resonance imaging (MRI) studies had revealed that the cyst had progressively enlarged. In addition, her memory disturbance had become advanced. Endoscopic cyst fenestration was performed between the cyst and lateral ventricle, resulting in a reduction of her symptoms. Our second patient was a 79-year-old woman with unsteadiness, who had presented with a large cyst under the right parietal convexity 6 years previously. The annual follow-up MRI studies had shown that the cyst had gradually enlarged. She subsequently developed left hemiparesis. Because the pyramidal tract was located between the cyst and ventricle, a cyst–ventricle shunt was placed to allow the cystic fluid into the lateral ventricle, with complete resolution of her symptoms. In both cases, MRI showed obliteration of the subdural spaces around the cysts. Endoscopic observations revealed that the arachnoid membrane was lined under the surrounding brain, leading to the diagnosis of an AC. Conclusion The establishment of stable communication between a cyst and the normal cerebrospinal fluid space is important to treat symptomatic ACs characterized by progressive enlargement, even in elderly patients. The 1-way entry of the cerebrospinal fluid into the cyst and the closure of the surrounding subdural space might result in AC enlargement internally.
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- 2020
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25. The critical role of the forest morphology for dry drawability of few-walled carbon nanotubes
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Masaki Hada, Yasuhiko Hayashi, Yoshifumi Yamashita, Tatsuki Marui, Kazuhiko Takahashi, Yoku Inoue, Takeshi Nishikawa, Hirotaka Inoue, and Tomohiro Nakagawa
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Imagination ,Chemical substance ,Materials science ,media_common.quotation_subject ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Thermal conductivity ,chemistry ,law ,Electrical resistivity and conductivity ,Ultimate tensile strength ,General Materials Science ,Composite material ,0210 nano-technology ,Science, technology and society ,Carbon ,media_common - Abstract
Carbon nanotube (CNT) yarns comprise few-walled CNTs (FWCNTs), mainly consisting of double- and triple-walled CNTs, and have several properties which are beneficial for practical bulk-scale carbon devices. These features include high tensile strength, electrical conductivity, thermal conductivity, chemical stability, and environmental tolerance. However, the synthesis window for fabricating CNT yarns with FWCNTs by the dry-spinning method is quite narrow and optimal conditions have yet to be determined. In this study, we fabricated CNT forests mainly comprised of FWCNTs at various synthesis conditions (temperature and time). The drawability of the CNT forests was characterized depending on the synthesis conditions. Our results show that optimum values exist for continuously drawable CNT forests in terms of both their height (>130 μm) and bulk density (>90 mg/cm3) for satisfying enough entanglement force between the CNT bundles. The diameter and number of walls of the CNTs are controlled by the temperature during the formation of catalyst particles because the sizes of catalyst particles are approximately equal to the outer diameter of CNTs. All temperature conditions in the range 350–500 °C, used to form catalyst particles, resulted in a drawable FWCNT forest. These insights will be useful for developing devices based on FWCNT yarns.
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- 2020
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26. A Review of Dry Spun Carbon Nanotube Yarns and Their Potential Applications in Energy and Mechanical Devices
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Hirotaka Inoue, Takeshi Nishikawa, Yusuke Chiba, Yasuhiko Hayashi, and Masaki Hada
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Materials science ,Polymers and Plastics ,law ,Materials Science (miscellaneous) ,Chemical Engineering (miscellaneous) ,Carbon nanotube ,Composite material ,Industrial and Manufacturing Engineering ,Energy (signal processing) ,Mechanical devices ,law.invention - Published
- 2020
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27. Reverse Engineering of Thin Films to Nanoparticles by Thermal Deposition for Large-Scale Production of Nanometals
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Marui Tatsuki, Zaw Lin, Yasuhiko Hayashi, Inoue Hirotaka, Karthik Paneer Selvam, and Takeshi Nishikawa
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Materials science ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Physical synthesis ,Thin film ,Metallic thin films ,0210 nano-technology ,Metal nanoparticles ,Thermal deposition - Abstract
A simple method to synthesize metal nanoparticles (Nps) has been proposed using high vacuum thermal deposition (HVTD) by reverse engineering of thin films to Nps. Metal Nps synthesized by this technique corresponds to the top-down approach of nanomaterial synthesis from bulk metals of silver and copper wires to metal Nps. A high-vacuum thermal deposition is a commonly used technique for thin-film deposition in many applications. Synthesis of metal Nps by HVTD is simple, efficient, and can provide particle of about few tens of nanometers is effortless. A precoated thin layer of polyethylene glycol (PEG) on a glass substrate (Petri dish), is allowed deposit with a metallic thin film by thermionically evaporating bulk metal wires in high vacuum. The deposited metal thin film is removed along with the PEG coating into a liquid medium and subjected to sonication, stirring, and deoxidation. Obtaining the particle size in tens of nanometer range in one step is one projecting factor by HVTD technique. Also, providing the feasibility of reusing large particles as precursors after synthesis is a unique vantage point. The Nps were analyzed by various characterizations tools to evaluate the underlying properties.
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- 2020
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28. Salvage Treatment for Intraoperative Bypass Occlusion during Superficial Temporal Artery-Middle Cerebral Artery Bypass Surgery
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Kouichi Misaki, Naoyuki Uchiyama, Yasuhiko Hayashi, Yasuhiro Aida, Masanao Mohri, and Mitsutoshi Nakada
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medicine.medical_specialty ,Bypass surgery ,business.industry ,medicine.artery ,Middle cerebral artery ,Salvage treatment ,Occlusion ,Medicine ,business ,Superficial temporal artery ,Surgery - Published
- 2020
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29. Single Crystals of Mixed‐Cation Copper‐Based Perovskite with Trimodal Bandgap Behavior
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Amr Elattar, Wenhui Li, Hiroo Suzuki, Takashi Kambe, Takeshi Nishikawa, Aung Ko Ko Kyaw, and Yasuhiko Hayashi
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Organic Chemistry ,General Chemistry ,Catalysis - Abstract
Two-dimensional (2D) hybrid perovskites with novel functionalities and structural diversity are a perfect platform for emerging optoelectronic devices such as photodetectors, light-emitting diodes, and solar cells. Here, we demonstrate that excess concentration of Cesium bromide (CsBr) is key to the formation of easily exfoliated 2D Cs
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- 2022
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30. Syndrome of inappropriate secretion of antidiuretic hormone as an initial sign of primary central nervous system lymphomas in the hypothalamus
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Masahiro Oishi, Yasuhiko Hayashi, Yasuo Sasagawa, Nozomu Oikawa, and Mitsutoshi Nakada
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Neurology (clinical) ,General Medicine - Abstract
Primary central nervous system lymphoma (PCNSL) rarely originates in the hypothalamus. Hypothalamic PCNSL can present with various symptoms specific to dysfunction of the hypothalamus, including consciousness disturbance, cognitive impairment, hypopituitarism, and diabetes insipidus (DI). However, it remains unclear whether syndrome of inappropriate secretion of antidiuretic hormone (SIADH) can present as an initial sign of hypothalamic PCNSL.Ninety-nine patients with PCNSL were diagnosed between January 2006 and December 2020 at our institutes. The initial symptoms and signs, hypothalamic-pituitary functions, serum sodium (Na) value, Karnofsky Performance Status (KPS) score on admission, and duration from onset to diagnosis were retrospectively investigated from the medical charts.Eight and 91 patients had hypothalamic PCNSL (hypothalamic group) and PCNSL located in other regions (control group), respectively. Patients' pathological diagnoses were diffuse large B-cell lymphoma (97 patients) and intravascular lymphoma (two patients). Six patients presented with hyponatremia derived from SIADH or suspected SIADH, and one presented with DI. Statistically significant differences between the hypothalamic and control groups were detected only in the preoperative serum Na values and KPS scores.SIADH can be an initial presentation of hypothalamic PCNSL. Early detection of hypothalamic PCNSL from SIADH may lead to proper management and improved prognosis.
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- 2022
31. Oxytocin Dynamics in the Body and Brain Regulated by the Receptor for Advanced Glycation End-Products, CD38, CD157, and Nicotinamide Riboside
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Haruhiro Higashida, Kazumi Furuhara, Olga Lopatina, Maria Gerasimenko, Osamu Hori, Tsuyoshi Hattori, Yasuhiko Hayashi, Stanislav M. Cherepanov, Anna A. Shabalova, Alla B. Salmina, Kana Minami, Teruko Yuhi, Chiharu Tsuji, PinYue Fu, Zhongyu Liu, Shuxin Luo, Anpei Zhang, Shigeru Yokoyama, Satoshi Shuto, Mizuki Watanabe, Koichi Fujiwara, Sei-ichi Munesue, Ai Harashima, and Yasuhiko Yamamoto
- Subjects
General Neuroscience - Abstract
Investigating the neurocircuit and synaptic sites of action of oxytocin (OT) in the brain is critical to the role of OT in social memory and behavior. To the same degree, it is important to understand how OT is transported to the brain from the peripheral circulation. To date, of these, many studies provide evidence that CD38, CD157, and receptor for advanced glycation end-products (RAGE) act as regulators of OT concentrations in the brain and blood. It has been shown that RAGE facilitates the uptake of OT in mother’s milk from the digestive tract to the cell surface of intestinal epithelial cells to the body fluid and subsequently into circulation in male mice. RAGE has been shown to recruit circulatory OT into the brain from blood at the endothelial cell surface of neurovascular units. Therefore, it can be said that extracellular OT concentrations in the brain (hypothalamus) could be determined by the transport of OT by RAGE from the circulation and release of OT from oxytocinergic neurons by CD38 and CD157 in mice. In addition, it has recently been found that gavage application of a precursor of nicotinamide adenine dinucleotide, nicotinamide riboside, for 12 days can increase brain OT in mice. Here, we review the evaluation of the new concept that RAGE is involved in the regulation of OT dynamics at the interface between the brain, blood, and intestine in the living body, mainly by summarizing our recent results due to the limited number of publications on related topics. And we also review other possible routes of OT recruitment to the brain.
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- 2022
32. Dispersion stability of tin(IV) oxide nanoparticles in polar solvents and water aided by ultrasonication
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Chinkhai Ong, Wengnam Lee, Linghong Lim, Wuyi Chong, Jingwen Chew, Yasuhiko Hayashi, Takeshi Nishikawa, Patrik Öhberg, Harith Ahmad, and Yuenkiat Yap
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General Engineering ,General Physics and Astronomy - Abstract
Dispersion stability of tin(IV) oxide nanoparticles dispersed in N-Methy-2-Pyrrolidone (NMP), dimethylformamide (DMF) and distilled water assisted by ultrasonication was investigated, aiming to identify a suitable liquid medium to effectively disperse tin(IV) oxide for many useful applications. The dispersions’ stability was characterized using field emission scanning electron microscopy, ultraviolet–visible spectroscopy and Zeta potential. The results show that distilled water has the highest stability with optimum sonication of 1 h. NMP shows better stability and consistency than DMF at different sonication timings. Good agreement between ultraviolet–visible absorbance and Zeta potentials shows that both distilled water and NMP are good mediums to produce highly stable tin(V) oxide dispersion.
- Published
- 2023
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33. LIF–IGF Axis Contributes to the Proliferation of Neural Progenitor Cells in Developing Rat Cerebrum
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Sho Takata, Hiromi Sakata-Haga, Hiroki Shimada, Tsuyoshi Tsukada, Daisuke Sakai, Hiroki Shoji, Mitsuhiro Tomosugi, Yuka Nakamura, Yasuhito Ishigaki, Hideaki Iizuka, Yasuhiko Hayashi, and Toshihisa Hatta
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Organic Chemistry ,General Medicine ,Leukemia Inhibitory Factor ,Catalysis ,Rats ,Receptor, IGF Type 1 ,Computer Science Applications ,Inorganic Chemistry ,Neural Stem Cells ,Pregnancy ,Insulin-Like Growth Factor II ,Somatomedins ,leukemia inhibitory factor ,insulin-like growth factor 1 ,insulin-like growth factor 2 ,cerebrum ,neural progenitor cell ,neurogenesis ,maternal immune activation ,psychiatric disorders ,Animals ,Female ,Insulin-Like Growth Factor I ,Physical and Theoretical Chemistry ,Cerebrum ,Molecular Biology ,Spectroscopy ,Cell Proliferation - Abstract
In rodent models, leukemia inhibitory factor (LIF) is involved in cerebral development via the placenta, and maternal immune activation is linked to psychiatric disorders in the child. However, whether LIF acts directly on neural progenitor cells (NPCs) remains unclear. This study performed DNA microarray analysis and quantitative RT-PCR on the fetal cerebrum after maternal intraperitoneal or fetal intracerebral ventricular injection of LIF at day 14.5 (E14.5) and determined that the expression of insulin-like growth factors (IGF)-1 and -2 was induced by LIF. Physiological IGF-1 and IGF-2 levels in fetal cerebrospinal fluid (CSF) increased from E15.5 to E17.5, following the physiological surge of LIF levels in CSF at E15.5. Immunostaining showed that IGF-1 was expressed in the cerebrum at E15.5 to E19.5 and IGF-2 at E15.5 to E17.5 and that IGF-1 receptor and insulin receptor were co-expressed in NPCs. Further, LIF treatment enhanced cultured NPC proliferation, which was reduced by picropodophyllin, an IGF-1 receptor inhibitor, even under LIF supplementation. Our findings suggest that IGF expression and release from the NPCs of the fetal cerebrum in fetal CSF is induced by LIF, thus supporting the involvement of the LIF–IGF axis in cerebral cortical development in an autocrine/paracrine manner.
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- 2022
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34. One-Minute Joule Annealing Enhances the Thermoelectric Properties of Carbon Nanotube Yarns via the Formation of Graphene at the Interface
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Chihiro Itoh, Hirotaka Inoue, Yoshifumi Yamashita, Taisuke Hasegawa, Toru Iijima, Naoshi Ikeda, Satoshi Maeda, Daiki Chujo, Takeshi Nishikawa, Kazuki Omoto, Kazuhiro Fujimori, Takuma Hayashi, Yasuhiko Hayashi, Shogo Iemoto, Toshihiko Kiwa, Taiga Morimoto, Masaki Hada, Taihei Kuroda, Shin-ya Koshihara, Tomoharu Tokunaga, and Makito Takagi
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Imagination ,Chemical substance ,Materials science ,Annealing (metallurgy) ,Graphene ,media_common.quotation_subject ,Energy Engineering and Power Technology ,Carbon nanotube ,law.invention ,Magazine ,law ,Thermoelectric effect ,Materials Chemistry ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering ,Composite material ,Science, technology and society ,media_common - Abstract
Interfaces in nanocarbon materials are highly important, as they determine the properties of carbon-based devices. In terms of carrier and thermal transport properties, the interfacial features are...
- Published
- 2019
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35. Ultrafast isomerization-induced cooperative motions to higher molecular orientation in smectic liquid-crystalline azobenzene molecules
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Ken Ishikawa, Tadahiko Ishikawa, Yasuhiko Hayashi, Takayoshi Sawa, Takashi Kato, Masaki Hada, Shin-ya Koshihara, Kenji Tsuruta, and Daisuke Yamaguchi
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Materials science ,Photoisomerization ,Polymers ,Science ,Physics::Optics ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Molecular dynamics ,Physics::Atomic and Molecular Clusters ,Ultraviolet light ,Molecule ,Soft matter ,Physics::Chemical Physics ,lcsh:Science ,Multidisciplinary ,Liquid crystals ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Electron diffraction ,Azobenzene ,chemistry ,Chemical physics ,lcsh:Q ,0210 nano-technology ,Isomerization - Abstract
The photoisomerization of molecules is widely used to control the structure of soft matter in both natural and synthetic systems. However, the structural dynamics of the molecules during isomerization and their subsequent response are difficult to elucidate due to their complex and ultrafast nature. Herein, we describe the ultrafast formation of higher-orientation of liquid-crystalline (LC) azobenzene molecules via linearly polarized ultraviolet light (UV) using ultrafast time-resolved electron diffraction. The ultrafast orientation is caused by the trans-to-cis isomerization of the azobenzene molecules. Our observations are consistent with simplified molecular dynamics calculations that revealed that the molecules are aligned with the laser polarization axis by their cooperative motion after photoisomerization. This insight advances the fundamental chemistry of photoresponsive molecules in soft matter as well as their ultrafast photomechanical applications., Photoisomerization of molecules is used to control the structure of soft matter but the response of molecules during isomerization is difficult to elucidate. Here the authors describe ultrafast formation of higher-orientation of liquid-crystalline azobenzene molecules via linearly polarized UV light using time-resolved electron diffraction.
- Published
- 2019
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36. Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode
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Ken Onda, Chihiro Itoh, Shin-ya Koshihara, Satoshi Ohmura, Ikufumi Katayama, Yusuke Arashida, Kiyoshi Miyata, Takayoshi Yokoya, Masaki Hada, Shota Mizote, Jun Takeda, Wang Chen, Yasuhiko Hayashi, Ryo Fukaya, Tomoharu Tokunaga, Kenji Tsuruta, Takayuki Suzuki, Yuta Nishina, Kohei Ichiyanagi, Takayoshi Sawa, Shin-ichi Adachi, Toshio Seki, Jiro Matsuo, and Shunsuke Nozawa
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Materials science ,Photon ,business.industry ,Graphene ,General Engineering ,Oxide ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Thermal ,Optoelectronics ,General Materials Science ,Selective reduction ,0210 nano-technology ,business - Abstract
A two-dimensional nanocarbon, graphene, has attracted substantial interest due to its excellent properties. The reduction of graphene oxide (GO) has been investigated for the mass production of gra...
- Published
- 2019
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37. Identification of GSK3β inhibitor kenpaullone as a temozolomide enhancer against glioblastoma
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Hemragul Sabit, Yu Dong, Tomohiro Kitabayashi, Masahiko Kobayashi, Guangtao Zhang, Shabierjiang Jiapaer, Yasuhiko Hayashi, Takuya Furuta, Toshinari Minamoto, Jiakang Zhang, Atsushi Hirao, Takahiro Domoto, and Mitsutoshi Nakada
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0301 basic medicine ,Indoles ,Combination therapy ,Cell Survival ,medicine.medical_treatment ,lcsh:Medicine ,Drug development ,Article ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Cancer stem cell ,GSK-3 ,Glioma ,Cell Line, Tumor ,medicine ,Temozolomide ,Animals ,Humans ,Viability assay ,lcsh:Science ,Protein Kinase Inhibitors ,Chemotherapy ,Multidisciplinary ,Glycogen Synthase Kinase 3 beta ,business.industry ,Brain Neoplasms ,lcsh:R ,Glycogen Synthase Kinases ,Benzazepines ,medicine.disease ,Xenograft Model Antitumor Assays ,CNS cancer ,030104 developmental biology ,Chemotherapy, Adjuvant ,Drug Resistance, Neoplasm ,Cancer research ,Neoplastic Stem Cells ,lcsh:Q ,Stem cell ,Drug Screening Assays, Antitumor ,business ,Glioblastoma ,030217 neurology & neurosurgery ,medicine.drug ,Signal Transduction - Abstract
Cancer stem cells are associated with chemoresistance and rapid recurrence of malignant tumors, including glioblastoma (GBM). Although temozolomide (TMZ) is the most effective drug treatment for GBM, GBM cells acquire resistance and become refractory to TMZ during treatment. Therefore, glioma stem cell (GSC)-targeted therapy and TMZ-enhancing therapy may be effective approaches to improve GBM prognosis. Many drugs that suppress the signaling pathways that maintain GSC or enhance the effects of TMZ have been reported. However, there are no established therapies beyond TMZ treatment currently in use. In this study, we screened drug libraries composed of 1,301 existing drugs using cell viability assays to evaluate effects on GSCs, which led to selection of kenpaullone, a kinase inhibitor, as a TMZ enhancer targeting GSCs. Kenpaullone efficiently suppressed activity of glycogen synthase kinase (GSK) 3β. Combination therapy with kenpaullone and TMZ suppressed stem cell phenotype and viability of both GSCs and glioma cell lines. Combination therapy in mouse models significantly prolonged survival time compared with TMZ monotherapy. Taken together, kenpaullone is a promising drug for treatment of GBM by targeting GSCs and overcoming chemoresistance to TMZ.
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- 2019
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38. Aqueductal Developmental Venous Anomaly Presenting with Mimic Symptoms of Idiopathic Normal Pressure Hydrocephalus in an Elderly Patient: A Case Report
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Daisuke Kita, Yasuhiko Hayashi, and Cheho Park
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medicine.medical_specialty ,developmental venous anomaly ,Urinary urgency ,business.industry ,aqueductal stenosis ,Cognitive disorder ,Endoscopic third ventriculostomy ,Case Report ,endoscopic third ventriculostomy ,medicine.disease ,Asymptomatic ,medicine.anatomical_structure ,obstructive hydrocephalus ,Aqueductal stenosis ,Ventricle ,Internal medicine ,medicine ,Cardiology ,medicine.symptom ,Headaches ,Vein ,business - Abstract
Developmental venous anomalies (DVAs) are generally asymptomatic; however, they can sometimes cause central nervous disorders. Aqueductal stenosis caused by DVAs is so rare that only 14 cases have been reported to date. Moreover, most patients are children or young adults, presenting with headaches or consciousness disturbances, associated with raised intracranial pressure. Here, we report on an 83-year-old man presenting with mimic symptoms of idiopathic normal pressure hydrocephalus (cognitive disorder, gait disturbance, and urinary urgency: Hakim's triad) because of obstructive hydrocephalus caused by a DVA located in the aqueduct. Endoscopic third ventriculostomy (ETV) was performed to relieve his symptoms, and the opening pressure of the lateral ventricle was recorded to be 10 cm-H2O. Endoscopic examination of the intraventricular system clearly revealed a vein within the aqueduct converging with the adjacent subependymal vessels. These findings were compatible with the characteristics of DVAs. His symptoms improved after the ETV. This case suggested that DVAs within the aqueduct, despite of their congenital nature, could give rise to decompensated obstructive hydrocephalus even in elderly patients, resulting in Hakim's triad.
- Published
- 2019
39. Temperature dependence of pressure-driven water permeation through membranes consisting of vertically-aligned double-walled carbon nanotube arrays
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Hirotaka Inoue, Yasuhiko Hayashi, Shaoling Zhang, Shiho Shirahama, Masaki Hada, Motohiro Aiba, Kenjiro Hata, Shuji Tsuruoka, and Hidetoshi Matsumoto
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Double walled ,Materials science ,02 engineering and technology ,General Chemistry ,Activation energy ,Carbon nanotube ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Membrane ,Chemical engineering ,law ,Permeability (electromagnetism) ,Molecule ,Inner diameter ,General Materials Science ,0210 nano-technology - Abstract
We explore the temperature dependence of pressure-driven water permeation through membranes consisting of a vertically aligned double-walled carbon nanotube (VA DWCNT) array. The prepared membrane with CNT inner diameter of 3.9 nm exhibits no water permeation below the critical temperature of 26 °C, after which water permeability is first observed and increases with temperatures >26 °C. Further, the critical temperature decreases to 18 °C when the CNT inner diameter increases to 6.0 nm. The water permeation in the CNT-confined space exhibits activation energy transitions around room temperature, thereby suggesting that the confined water molecules in CNTs exhibit plural ordered structures.
- Published
- 2019
40. Suprasellar Colloid Cyst over 11-Year Follow-up: Case Report and Literature Review
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Mitsutoshi Nakada, Takehiro Uno, Tadao Miyamori, Yasuhiko Hayashi, Masahiro Oishi, and Yasuo Sasagawa
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medicine.medical_specialty ,Suprasellar region ,Third ventricle ,medicine.diagnostic_test ,Colloid cyst ,business.industry ,Head injury ,Magnetic resonance imaging ,medicine.disease ,Asymptomatic ,Lesion ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,medicine ,Surgery ,Cyst ,Neurology (clinical) ,Radiology ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Background Colloid cysts (CCs) are rare cystic lesions derived from the endoderm of the central nervous system. Although they appear most commonly in the anterior roof of the third ventricle, there are only a few reports of CCs located in the suprasellar region. Although CCs are considered to be slow-growing benign tumors, their developmental process remains unclear. Case Description A 6-year-old boy was referred to our hospital for a mild head injury. Head computed tomography scan revealed a round, hyperdense suprasellar lesion, while magnetic resonance imaging depicted the mass as an isointense lesion with multiple highly hypointense spots on T2-weighted imaging. Although this lesion had been managed conservatively with annual magnetic resonance imaging follow-up, its size gradually increased, resulting in an increase in diameter by a factor of 1.5 over an 11-year period. The doubling time of this tumor was estimated to be approximately 7 years. Despite its asymptomatic nature, the cystic lesion was totally resected when the patient was 17 years of age using an endoscopic endonasal approach to make a definitive histologic diagnosis and prevent the occurrence of neurologic symptoms. The postoperative course was uneventful, and the histologic diagnosis of the surgical specimen was consistent with CC. Conclusions This case suggests that CC may be one of several possible diagnoses in patients who present with suprasellar cystic lesions. Even if CCs in the suprasellar region remain asymptomatic, radiological follow-up is required due to possible progressive enlargement of the cyst.
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- 2019
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41. Association between J‐CTO score and long‐term target lesion revascularization rate after successful chronic total coronary occlusion angioplasty (from the J‐CTO Registry)
- Author
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Yuichi Noguchi, Osamu Doi, Mitsuru Abe, Tomoaki Hinohara, Takeshi Morimoto, Toshiya Muramatsu, Hiroyuki Tanaka, Kazushige Kadota, J-Cto Registry Investigators, Yoshikazu Hiasa, Yoshihiro Morino, Yoshisato Shibata, Takeshi Kimura, Kazuhiko Yumoto, Masaharu Akao, Yasuhiko Hayashi, Takehiro Yamashita, and Masahiko Ochiai
- Subjects
Male ,medicine.medical_specialty ,Time Factors ,medicine.medical_treatment ,030204 cardiovascular system & hematology ,Coronary Angiography ,Risk Assessment ,Decision Support Techniques ,03 medical and health sciences ,Percutaneous Coronary Intervention ,0302 clinical medicine ,Japan ,Predictive Value of Tests ,Risk Factors ,Interquartile range ,Internal medicine ,Angioplasty ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Cumulative incidence ,Prospective Studies ,Registries ,030212 general & internal medicine ,Aged ,business.industry ,Percutaneous coronary intervention ,General Medicine ,Odds ratio ,Middle Aged ,Confidence interval ,Treatment Outcome ,Coronary Occlusion ,Coronary occlusion ,Chronic Disease ,Conventional PCI ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Objectives The aim of this study was to evaluate the impact of the J-CTO score on long-term target lesion revascularization (TLR) after successful native chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). Background We previously reported that the J-CTO score could be used to stratify the lesion complexity and procedural success rate in CTO lesions. Methods We evaluated the prognostic significance of a high J-CTO score for long-term TLR rate in the J-CTO Registry. Results In the 425 lesions of 408 patients who underwent successful CTO-PCI during a median follow-up of 63.0 (interquartile range: 21.2-72.9) months in the J-CTO Registry, the cumulative incidence of TLR of lesions with a J-CTO score ≥ 2 (n = 216) was significantly higher than in those with a J-CTO score ≤ 1 (n = 209) (27.0 versus 19.4% at 5 years, respectively, P = 0.04). Among 323 lesions of 309 patients with a complete 5-year follow-up, the rate of TLR was 28% (n = 91). A J-CTO score ≥ 2 was independently associated with a higher risk of TLR (odds ratio, 1.73; 95% confidence interval, 1.01-2.99, P = 0.048) even after adjustment for clinically relevant baseline factors. Conclusions Patients with high J-CTO score lesions had a higher 5-year risk of TLR.
- Published
- 2019
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42. Directional Regulation of Extrasellar Extension by Sellar Dura Integrity and Intrasphenoidal Septation In Pituitary Adenomas
- Author
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Fumiaki Ueda, Daisuke Kita, Yasuo Sasagawa, Masahiro Oishi, Yasuhiko Hayashi, Osamu Tachibana, Shingo Tanaka, and Mitsutoshi Nakada
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Adenoma ,Male ,Posterior clinoid processes ,Dura mater ,Pituitary neoplasm ,03 medical and health sciences ,0302 clinical medicine ,Pituitary adenoma ,medicine ,Humans ,Pituitary Neoplasms ,Sella Turcica ,Sinus (anatomy) ,Retrospective Studies ,business.industry ,Anatomy ,Middle Aged ,medicine.disease ,Tumor Burden ,medicine.anatomical_structure ,Sella turcica ,030220 oncology & carcinogenesis ,Cavernous sinus ,Disease Progression ,Female ,Surgery ,Dura Mater ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
Objective Pituitary macroadenomas extend into the extrasellar space, such as the sphenoid sinus, cavernous sinuses, and suprasellar region. However, factors that regulate the direction of their extensions into the surrounding anatomical structures remain unknown. Methods This retrospective study included 162 patients who were treated for pituitary adenomas that had maximum diameters greater than 20 mm. According to the direction of adenoma extension, patients were divided into 4 groups: group A, inferior into the sphenoid sinus; group B, lateral into the cavernous sinus; group C, suprasellar region with enlarged sella turcica; and group D, supraellar region without enlarged sella turcica. Several anatomical structures surrounding the sella turcica were evaluated statistically, and multivariate logistic regression analysis was performed if the structures met the determining factors of adenomas extensions. Results The maximum diameter of adenomas was significantly larger in groups A and D. The maximum diameter of the diaphragmatic foramen was largest in group C (19.3 mm) and was significantly narrower in groups B (12.7 mm) and D (12.5 mm). Intrasphenoid septation, attached on the midline of the sella turcica, was observed most frequently in group D (78.6%) and was not detectable in group A (0%). Extension into the cavernous sinus, classified as dural discontinuity, was highly prevalent in group B (80.0%) and was uncommon in group C (12.3%). Erosion of the posterior clinoid process was most apparent in group B (92.0%). Conclusions The integrity of the sella dura and the intrasphenoid septation can regulate adenoma extension by encouraging their growth towards paths of least resistance.
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- 2019
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43. Traumatic retroclival epidural hematoma associated with reversible ipsilateral internal carotid artery stenosis
- Author
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Akira Tamase, Hideaki Iizuka, Hirotaka Shojima, Sho Takata, and Yasuhiko Hayashi
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Adult ,Hematoma, Epidural, Cranial ,medicine.medical_specialty ,Subarachnoid hemorrhage ,Epidural hematoma ,Hematoma ,medicine.artery ,medicine ,Humans ,Carotid Stenosis ,cardiovascular diseases ,Child ,Abducens nerve ,Palsy ,business.industry ,General Medicine ,medicine.disease ,Hematoma, Epidural, Spinal ,Magnetic Resonance Imaging ,Epidural space ,Stenosis ,medicine.anatomical_structure ,Pediatrics, Perinatology and Child Health ,cardiovascular system ,Female ,Neurology (clinical) ,Radiology ,Internal carotid artery ,business ,Tomography, X-Ray Computed ,Carotid Artery, Internal - Abstract
Traumatic retroclival epidural hematoma is rare. It is more common in pediatrics than in adults. Although it has been known that these cases are frequently associated with abducens nerve palsy, internal carotid artery stenosis is rarely found with those hematomas. An 8-year-old girl was transferred to our hospital following a traffic accident. She had clear consciousness with right abducens nerve palsy. Computed tomography revealed the left side of both retroclival hematoma without clival fracture and subarachnoid hemorrhage at the Sylvian fissure. She also had a fracture of left femoral neck and ipsilateral lung contusion. Magnetic resonance imaging revealed a retroclival hematoma located in the epidural space and severe stenosis of left internal carotid artery (ICA) from the cavernous to supraclinoid portion without evidence of brain contusion. She was managed conservatively, and her right abducens nerve palsy recovered completely without deterioration of other neurological findings. Neuroradiological findings suggested this ICA stenosis as traumatic dissection. She was discharged home 2 months after the traffic accident. Retroclival epidural hematoma without clival fracture associated with ipsilateral ICA stenosis is extremely rare. Although the exact mechanism of the ICA stenosis remains unclear, cerebral vascular events should be considered in the cases with traumatic retroclival hematoma.
- Published
- 2021
44. Pediatric meningioma with rhabdoid features developed at the site of skull fracture: illustrative case
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Akira Tamase, Yasuhiko Hayashi, Osamu Tachibana, Katsuaki Sato, Hideaki Iizuka, and Sho Takata
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medicine.medical_specialty ,Skull fracture ,business.industry ,otorhinolaryngologic diseases ,medicine ,General Medicine ,Radiology ,Pediatric meningioma ,medicine.disease ,business - Abstract
BACKGROUND Pediatric meningiomas are rare, and only a few cases attributed to trauma and characterized by development at the site of bone fracture have been reported. Both pediatric and traumatic meningiomas have aggressive characteristics. OBSERVATIONS An 11-year-old boy who sustained a head injury resulting from a left frontal skull fracture 8 years previously experienced a convulsive attack. Imaging revealed a meningioma in the left frontal convexity. Total removal of the tumor with a hyperostotic section was successfully achieved. Intraoperative investigation showed tumor invasion into the adjacent frontal cortex. Histologically, the surgical specimen revealed a transitional meningioma with brain invasion and a small cluster of rhabdoid cells. This led to a final pathological diagnosis of an atypical meningioma with rhabdoid features. The postoperative course was uneventful, and no recurrence of the tumor was found after 2 years without adjuvant therapy. LESSONS This is the first report of a pediatric meningioma with rhabdoid features occurring at the site of a skull fracture. Meningiomas that contain rhabdoid cells without malignant features are not considered to be as aggressive as rhabdoid meningiomas. However, the clinical course must be carefully observed for possible long-term tumor recurrence.
- Published
- 2021
45. Generation of sub-100 fs electron pulses for time-resolved electron diffraction using a direct synchronization method
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Kou Takubo, Samiran Banu, Sichen Jin, Misaki Kaneko, Wataru Yajima, Makoto Kuwahara, Yasuhiko Hayashi, Tadahiko Ishikawa, Yoichi Okimoto, Masaki Hada, and Shinya Koshihara
- Subjects
Physics::Optics ,Instrumentation - Abstract
To investigate photoinduced phenomena in various materials and molecules, ultrashort pulsed x-ray and electron sources with high brightness and high repetition rates are required. The x-ray and electron’s typical and de Broglie wavelengths are shorter than lattice constants of materials and molecules. Therefore, photoinduced structural dynamics on the femtosecond to picosecond timescales can be directly observed in a diffraction manner by using these pulses. This research created a tabletop ultrashort pulsed electron diffraction setup that used a femtosecond laser and electron pulse compression cavity that was directly synchronized to the microwave master oscillator (∼3 GHz). A compressed electron pulse with a 1 kHz repetition rate contained 228 000 electrons. The electron pulse duration was estimated to be less than 100 fs at the sample position by using photoinduced immediate lattice changes in an ultrathin silicon film (50 nm). The newly developed time-resolved electron diffraction setup has a pulse duration that is comparable to femtosecond laser pulse widths (35–100 fs). The pulse duration, in particular, fits within the timescale of photoinduced phenomena in quantum materials. Our developed ultrafast time-resolved electron diffraction setup with a sub-100 fs temporal resolution would be a powerful tool in material science with a combination of optical pump–probe, time-resolved photoemission spectroscopic, and pulsed x-ray measurements.
- Published
- 2022
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46. Surgical Outcomes of Incidental Pituitary Adenomas in Elderly Patients
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Yasuo Sasagawa, Ryouken Kimura, Yasuhiko Hayashi, and Mitsutoshi Nakada
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medicine.medical_specialty ,medicine.diagnostic_test ,Adenoma ,business.industry ,medicine.disease ,Preoperative care ,Endoscopy ,Surgery ,Health evaluation ,Pituitary adenoma ,medicine ,Tumor growth ,Neurology (clinical) ,Hormone replacement therapy ,business ,Meningitis - Published
- 2020
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47. In Reply to the Letter to the Editor Regarding 'Evaluation of Soft Tissue Hypertrophy at the Retro-Odontoid Space in Patients with Chiari Malformation Type I on Magnetic Resonance Imaging'
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Masahiro Oishi, Kazuto Kosaka, Yasuhiko Hayashi, Daisuke Kita, Mitsutoshi Nakada, and Yasuo Sasagawa
- Subjects
medicine.medical_specialty ,Letter to the editor ,medicine.diagnostic_test ,business.industry ,Soft tissue ,Magnetic resonance imaging ,Hypertrophy ,Magnetic Resonance Imaging ,Syringomyelia ,Muscle hypertrophy ,Arnold-Chiari Malformation ,CHIARI MALFORMATION TYPE I ,Odontoid Process ,Medicine ,Humans ,Surgery ,In patient ,Neurology (clinical) ,Radiology ,business - Published
- 2020
48. Synthesis and characterization of conductive flexible cellulose carbon nanohorn sheets for human tissue applications
- Author
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Toshiyuki Nakamura, Taichi Nagahata, Takeshi Nishikawa, Ayano Satoh, Karthik Paneer Selvam, Mayuko Koreishi, Yoshimasa Nakamura, Kosuke Kato, and Yasuhiko Hayashi
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lcsh:Medical technology ,Materials science ,Scanning electron microscope ,Composite number ,Biomedical Engineering ,Medicine (miscellaneous) ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Carbon Nanohorns ,Biomaterials ,chemistry.chemical_compound ,symbols.namesake ,Ultimate tensile strength ,Cellulose ,Fourier transform infrared spectroscopy ,Bio-compatible ,Composites ,Biomaterial ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,lcsh:R855-855.5 ,chemistry ,Chemical engineering ,Transmission electron microscopy ,Ceramics and Composites ,symbols ,0210 nano-technology ,Raman spectroscopy ,Skin sensitization ,Research Article - Abstract
Background Conductive sheets of cellulose and carbon nanomaterials and its human skin applications are an interesting research aspect as they have potential for applications for skin compatibility. Hence it is needed to explore the effects and shed light on these applications. Method To fabricate wearable, portable, flexible, lightweight, inexpensive, and biocompatible composite materials, carbon nanohorns (CNHs) and hydroxyethylcellulose (HEC) were used as precursors to prepare CNH-HEC (Cnh-cel) composite sheets. Cnh-cel sheets were prepared with different loading concentrations of CNHs (10, 20 50,100 mg) in 200 mg cellulose. To fabricate the bio-compatible sheets, a pristine composite of CNHs and HEC was prepared without any pretreatment of the materials. Results The obtained sheets possess a conductivity of 1.83 × 10− 10 S/m and bio-compatible with human skin. Analysis for skin-compatibility was performed for Cnh-cel sheets by h-CLAT in vitro skin sensitization tests to evaluate the activation of THP-1 cells. It was found that THP-1 cells were not activated by Cnh-cel; hence Cnh-cel is a safe biomaterial for human skin. It was also found that the composite allowed only a maximum loading of 100 mg to retain the consistent geometry of free-standing sheets of Conclusion It can be concluded that cellulose and CNHs sheets are conductive and compatible to human skin applications.
- Published
- 2020
- Full Text
- View/download PDF
49. Oculomotor nerve palsy in pituitary apoplexy associated with pituitary adenoma: a radiological analysis with fast imaging employing with steady-state acquisition
- Author
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Masahiro Oishi, Mitsutoshi Nakada, Kazumasa Ooiso, Yasuhiko Hayashi, Hiroyuki Aburano, and Yasuo Sasagawa
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Adenoma ,Adult ,Male ,medicine.medical_specialty ,Neurology ,genetic structures ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Oculomotor Nerve ,Pituitary adenoma ,medicine ,Oculomotor Nerve Diseases ,Humans ,Pituitary Neoplasms ,Oculomotor nerve palsy ,Neuroradiology ,Aged ,Retrospective Studies ,Oculomotor nerve ,business.industry ,Pituitary apoplexy ,Middle Aged ,medicine.disease ,Radiography ,Cavernous sinus ,Surgery ,Cavernous Sinus ,Female ,Neurology (clinical) ,Radiology ,Neurosurgery ,business ,Pituitary Apoplexy ,030217 neurology & neurosurgery - Abstract
Oculomotor nerve palsy (ONP) occasionally occurs in cases of pituitary apoplexy (PA) associated with pituitary adenoma, but its mechanism remains unclear. Intracranial nerves are clearly visualized by fast-imaging employing with steady-state acquisition (FIESTA). Here, we assessed the oculomotor nerve compression in patients with PA associated with pituitary adenoma using FIESTA. Twenty-eight cases of PA, with or without ONP, were retrospectively reviewed. All patients had undergone preoperative FIESTA. Two neuroradiologists, unaware of the patient’s clinical symptoms, evaluated the presence and location of oculomotor nerve compression due to the tumor. Thirteen of the twenty-eight PA cases were associated with ONP. Tumor size and degree of cavernous sinus invasion were not significantly different between the ONP and non-ONP groups. Even in the ONP group, 8/13 (62%) tumors did not show cavernous sinus invasion. Via FIESTA, the presence of oculomotor nerve compression was confirmed in 11/13 (85%) and 5/15 (33%) cases in the ONP and non-ONP groups, respectively (p = 0.008). The radiologists’ diagnoses of laterality of nerve compression (right or left) were consistent with the patient’s affected eye. In the ONP group, the location of the nerve compression was located at the entry point to the cavernous sinus, the so-called oculomotor triangle, in 9/11 (82%) cases and intra cavernous sinus in 2/11 (18%) cases. Compression at the oculomotor triangle is considered the main cause of ONP with PA in pituitary adenomas.
- Published
- 2020
50. Synthesis and Characterization of Human Skin-Compatible Conductive Flexible Cellulose Carbon Nanohorn Sheets
- Author
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Toshiyuki Nakamura, Yasuhiko Hayashi, Yoshimasa Nakamura, Karthik Paneer Selvam, Ayano Satoh, Mayuko Koreishi, Kosuke Kato, Taichi Nagahata, and Takeshi Nishikawa
- Subjects
Carbon Nanohorn ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Human skin ,Cellulose ,Electrical conductor ,Characterization (materials science) - Abstract
Background: Conductive sheets of cellulose and carbon nanomaterials and its human skin applications are an interesting research aspect as they have potential for applications for skin compatibility. Hence it is needed to explore the effects and shed light on these applications.Method: To fabricate wearable, portable, flexible, lightweight, inexpensive, and biocompatible composite materials, carbon nanohorns (CNHs) and hydroxyethylcellulose (HEC) were used as precursors to prepare CNH-HEC (Cnh-cel) composite sheets. Cnh-cel sheets were prepared with different loading concentrations of CNHs (10, 20 50,100 mg) in 200 mg cellulose. To fabricate the bio-compatible sheets, a pristine composite of CNHs and HEC was prepared without any pretreatment of the materials. Results: The obtained sheets are conductive (1.83×10-5 S) and bio-compatible with human skin. Analysis for skin-compatibility was performed for Cnh-cel sheets by h-CLAT in vitro skin sensitization tests to evaluate the activation of THP-1 cells. It was found that THP-1 cells were not activated by Cnh-cel; hence Cnh-cel is a safe biomaterial for human skin. It was also found that the composite allowed only a maximum loading of 100 mg to retain the consistent geometry of free-standing sheets of < 100 µm thickness. Since CNHs have a unique arrangement of aggregates (dahlia structure), the composite is homogeneous, as verified by transmission electron microscopy (TEM) and, scanning electron microscopy (SEM), and other functional properties investigated by Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), conductance measurement, tensile strength measurement, and skin sensitization.Conclusion: It can be concluded that cellulose and CNHs sheets are conductive and compatible to human skin applications.
- Published
- 2020
- Full Text
- View/download PDF
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