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TURBULENCE PRODUCED BY TSUNAMIS IN GALAXY CLUSTERS
FUJITA YUTAKA,MATSUMOTO TOMOAKI,WADA KEIICHI The Korean Astronomical Society 2004 Journal of The Korean Astronomical Society Vol.37 No.5
Clusters of galaxies are filled with X-ray emitted hot gas with the temperature of T ${\~}$2-10 keV. Recent X-ray observations have been revealing unexpectedly that many cluster cores have complicated, peculiar X-ray structures, which imply dynamical motion of the hot gas. Moreover, X-ray spectra indicate that radiative cooling of the cool gas is suppressed by unknown heating mechanisms (the 'cooling flow problem'). Here we propose a novel mechanism reproducing both the inhomogeneous structures and dynamics of the hot gas in the cluster cores, based on state-of-the-art hydrodynamic simulations. We showed that acoustic-gravity waves, which are naturally expected during the process of hierarchical structure formation of the universe, surge in the X-ray hot gas, causing a serous impact on the core. This reminds us of tsunamis on the ocean surging into an distant island. We found that the waves create fully-developed, stable turbulence, which reproduces the complicated structures in the core. Moreover, if the wave amplitude is large enough, they can suppress the cooling of the core. The turbulence could be detected in near-future space X-ray missions such as ASTRO-E2.
The role of curvature in silica mesoporous crystals
Miyasaka, Keiichi,Garcia Bennett, Alfonso,Han, Lu,Han, Yu,Xiao, Changhong,Fujita, Nobuhisa,Castle, Toen,Sakamoto, Yasuhiro,Che, Shunai,Terasaki, Osamu The Royal Society 2012 Interface focus Vol.2 No.5
<P>Silica mesoporous crystals (SMCs) offer a unique opportunity to study micellar mesophases. Replication of non-equilibrium mesophases into porous silica structures allows the characterization of surfactant phases under a variety of chemical and physical perturbations, through methods not typically accessible to liquid crystal chemists. A poignant example is the use of electron microscopy and crystallography, as discussed herein, for the purpose of determining the fundamental role of amphiphile curvature, namely mean curvature and Gaussian curvature, which have been extensively studied in various fields such as polymer, liquid crystal, biological membrane, etc. The present work aims to highlight some current studies devoted to the interface curvature on SMCs, in which electron microscopy and electron crystallography (EC) are used to understand the geometry of silica wall surface in bicontinuous and cage-type mesostructures through the investigation of electrostatic potential maps. Additionally, we show that by altering the synthesis conditions during the preparation of SMCs, it is possible to isolate particles during micellar mesophase transformations in the cubic bicontinuous system, allowing us to view and study epitaxial relations under the specific synthesis conditions. By studying the relationship between mesoporous structure, interface curvature and micellar mesophases using electron microscopy and EC, we hope to bring new insights into the formation mechanism of these unique materials but also contribute a new way of understanding periodic liquid crystal systems.</P>
Dodecagonal tiling in mesoporous silica
Xiao, Changhong,Fujita, Nobuhisa,Miyasaka, Keiichi,Sakamoto, Yasuhiro,Terasaki, Osamu Nature Publishing Group, a division of Macmillan P 2012 Nature Vol.487 No.7407
Recent advances in the fabrication of quasicrystals in soft matter systems have increased the length scales for quasicrystals into the mesoscale range (20 to 500 책ngstr철ms). Thus far, dendritic liquid crystals, ABC-star polymers, colloids and inorganic nanoparticles have been reported to yield quasicrystals. These quasicrystals offer larger length scales than intermetallic quasicrystals (a few 책ngstr철ms), thus potentially leading to optical applications through the realization of a complete photonic bandgap induced via multiple scattering of light waves in virtually all directions. However, the materials remain far from structurally ideal, in contrast to their intermetallic counterparts, and fine control over the structure through a self-organization process has yet to be attained. Here we use the well-established self-assembly of surfactant micelles to produce a new class of mesoporous silicas, which exhibit 12-fold (dodecagonal) symmetry in both electron diffraction and morphology. Each particle reveals, in the 12-fold cross-section, an analogue of dodecagonal quasicrystals in the centre surrounded by 12 fans of crystalline domains in the peripheral part. The quasicrystallinity has been verified by selected-area electron diffraction and quantitative phason strain analyses on transmission electron microscope images obtained from the central region. We argue that the structure forms through a non-equilibrium growth process, wherein the competition between different micellar configurations has a central role in tuning the structure. A simple theoretical model successfully reproduces the observed features and thus establishes a link between the formation process and the resulting structure.
A review of fine structures of nanoporous materials as evidenced by microscopic methods.
Liu, Zheng,Fujita, Nobuhisa,Miyasaka, Keiichi,Han, Lu,Stevens, Sam M,Suga, Mitsuo,Asahina, Shunsuke,Slater, Ben,Xiao, Changhong,Sakamoto, Yasuhiro,Anderson, Michael W,Ryoo, Ryong,Terasaki, Osamu Oxford University Press 2013 Microscopy Vol.62 No.1
<P>This paper reviews diverse capabilities offered by modern electron microscopy techniques in studying fine structures of nanoporous crystals such as zeolites, silica mesoporous crystals, metal organic frameworks and yolk-shell materials. For the case of silica mesoporous crystals, new approaches that have been developed recently to determine the three-dimensionally periodic average structure, e.g., through self-consistent analysis of electron microscope images or through consideration of accidental extinctions, are presented. Various structural deviations in nanoporous materials from their average structures including intergrowth, surface termination, incommensurate modulation, quasicrystal and defects are demonstrated. Ibidem observations of the scanning electron microscope and atomic force microscope give information about the zeolite-crystal-growth mechanism, and an energy for unstitching a building-unit from a crystal surface is directly observed by an anatomic force microscope. It is argued how these observations lead to a deeper understanding of the materials.</P>
A System Concept for EFD/CFD Integration
Shigeya Watanabe,Shigeru Kuchi-ishi,Hiroyuki Kato,Takeshi Aoyama,Keiichi Murakami,Atsushi Hashimoto,Naoyuki Fujita,Yuichi Matsuo 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
A trail towards integration of EFD (Experimental Fluid Dynamics) and CFD (Computational Fluid Dynamics), that is. the development of a system called Digital/Analog Hybrid Wind Tunnel, is introduced. The aim of the system is to improve efficiency, accuracy, and reliability of aerodynamic characteristics evaluation in aerospace vehicle developments through mutual support between EFD and CFD. The function of the system consists of optimization of test planning utilizing pretest CFD calculations, an accurate correction of the wind tunnel wall and support interaction effects through CFD, CFD data refinement based on EFD data, the most probable aerodynamic characteristics estimation based on both EFD and CFD data, database including EFD and CFD data at an identical condition, and so forth. Key technical challenges in the system development, such as an automatic grid generation and high-speed solver development for CFD, a highly efficient data reduction technique for image measurement data. and techniques integrating EFD and CFD. are addressed.
A New Cancer Cell Detection Method Using an Infectivity-enhanced Adenoviral Vector
Uchino, Junji,Takayama, Koichi,Nakagaki, Noriaki,Shuo, Wang,Hisasue, Junko,Nakatom, Keita,Ohta, Keiichi,Hirano, Ryosuke,Tashiro, Naoki,Miiru, Izumi,Fujita, Masaki,Watanabe, Kentaro,Nakanishi, Yoichi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11
Cytological examination is widely used as a diagnostic tool because of the ease of collecting cells from the involved area. However, the diagnostic yield of cytological examination is unsatisfactory; the reasons include sampling error, poorly prepared samples, small numbers of malignant cells, and low grades of cellular atypia. In this study, we focused on the high infectivity of adenovirus towards epithelial cells and applied the luciferase-expressing adenoviral vector to a new cancer cell detection tool. In addition, adenoviral infectivity was enhanced by modifying viral fiber proteins. The sensitivity of the diagnostic tool was tested using the NCI-H1299 lung cancer cell line, and validated in body fluid samples from cancer patients with a variety of etiology. Results showed that the adenovirus efficiently transfected NCI-H1299 with high sensitivity. Only 10 cancer cells were sufficient for detection of luciferase signals. In body fluid samples, the adenovirus confirmed the diagnosis for malignant and benign cancer, but not in non-epithelial cell derived samples. This study provides proof-of-concept for a more reliable and sensitive diagnostic tool for epithelium-derived cancer.
Uchino, Junji,Hirano, Ryosuke,Tashiro, Naoki,Yoshida, Yuji,Ushijima, Shinichiro,Matsumoto, Takemasa,Ohta, Keiichi,Nakatomi, Keita,Takayama, Koichi,Fujita, Masaki,Nakanishi, Yoichi,Watanabe, Kentaro Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8
Aims and Background: To evaluate the efficacy of a combination of aprepitant and conventional antiemetic therapy in patients with advanced or recurrent lung cancer receiving moderately emetogenic chemotherapy (MEC). Methods: Patients with advanced or recurrent lung cancer who were treated with MEC regimens at the Department of Respiratory Medicine, Fukuoka University Hospital, were included and classified into the following groups: control group (treatment: 5-HT3 receptor antagonists + dexamethasone) and aprepitant group (treatment: 5-HT3 receptor antagonists + dexamethasone + aprepitant). The presence or absence of chemotherapy-induced nausea and vomiting (CINV) was evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.0; patients with grade 1 or above were considered positive for CINV. Food intake per day, completion of planned chemotherapy, and progression-free survival (PFS) achieved by chemotherapy were investigated. Results: The complete suppression rate of nausea in the aprepitant group was significantly higher than that in the control group (p = 0.0043). Throughout the study, the food intake in the aprepitant group was greater than that in the control group, with the rate being significantly higher, in particular, on day 5 (p = 0.003). The completion rate of planned chemotherapy was also higher in the aprepitant group (p = 0.042). PFS did not differ significantly, but tended to be improved in the aprepitant group. Conclusions: The aprepitant group showed significantly higher complete suppression of nausea, food intake on day 5, and completion of planned chemotherapy than the control group.