106 research outputs found

    Anti-Phase Domains in Gold-Copper-Zinc Ordered Alloys Revealed by Electron Microscope

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    Using thin evaporated films of gold-copper-zinc ternary ordered alloys, the line-up of anti-phase domains has been observed as parallel lines on transmission electron micrographs of bright field, down to a domain size of about 8A. The lattice modulation accompanying anti-phase domains, i. e. the periodic error of lattice spacing or scattering factor with the same period as a domain size, has again been verified to play an important role in forming the satellites around the direct spot on a diffraction pattern, and hence, in forming the parallel lines on electron-microscopic images. Two-thirds of the intensity of the satellites have been estimated in the present alloy films to arise from the modulation, and the rest probably from double diffraction

    STUDY ON APPLICATION OF DRAG-REDUCING TRIMETHYLOLETHANE SLURRY IN DISTRICR COOLING SYSTEM

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    Trimethylolethane (TME) trihydrate slurry is a proper phase-change material for latent heat transportation in cooling systems since it has excellence heat transfer performance and high thermal capacity. Additives, oleyl bishydroxyethyl methyl ammonium chloride (as surfactant) and sodium salicylate (as counter-ion), were used as drag-reducer substance. These additives not only induce drag reduction in TME slurry, but also control particle growth and agglomeration. In this study, energy saving estimation of drag-reducing TME slurry application in district cooling system is invesitgated. It is found that drag-reducing TME slurry gives remarkable pumping power suppresion in the district cooling system. To maintain high performance of heat exchangers, heat transfer enhancement technique may be needed in those exchangers

    Cationized gelatin-HVJ envelope with sodium borocaptate improved the BNCT efficacy for liver tumors in vivo

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    <p>Abstract</p> <p>Background</p> <p>Boron neutron capture therapy (BNCT) is a cell-selective radiation therapy that uses the alpha particles and lithium nuclei produced by the boron neutron capture reaction. BNCT is a relatively safe tool for treating multiple or diffuse malignant tumors with little injury to normal tissue. The success or failure of BNCT depends upon the <sup>10</sup>B compound accumulation within tumor cells and the proximity of the tumor cells to the body surface. To extend the therapeutic use of BNCT from surface tumors to visceral tumors will require <sup>10</sup>B compounds that accumulate strongly in tumor cells without significant accumulation in normal cells, and an appropriate delivery method for deeper tissues.</p> <p>Hemagglutinating Virus of Japan Envelope (HVJ-E) is used as a vehicle for gene delivery because of its high ability to fuse with cells. However, its strong hemagglutination activity makes HVJ-E unsuitable for systemic administration.</p> <p>In this study, we developed a novel vector for <sup>10</sup>B (sodium borocaptate: BSH) delivery using HVJ-E and cationized gelatin for treating multiple liver tumors with BNCT without severe adverse events.</p> <p>Methods</p> <p>We developed cationized gelatin conjugate HVJ-E combined with BSH (CG-HVJ-E-BSH), and evaluated its characteristics (toxicity, affinity for tumor cells, accumulation and retention in tumor cells, boron-carrying capacity to multiple liver tumors <it>in vivo</it>, and bio-distribution) and effectiveness in BNCT therapy in a murine model of multiple liver tumors.</p> <p>Results</p> <p>CG-HVJ-E reduced hemagglutination activity by half and was significantly less toxic in mice than HVJ-E. Higher <sup>10</sup>B concentrations in murine osteosarcoma cells (LM8G5) were achieved with CG-HVJ-E-BSH than with BSH. When administered into mice bearing multiple LM8G5 liver tumors, the tumor/normal liver ratios of CG-HVJ-E-BSH were significantly higher than those of BSH for the first 48 hours (<it>p < 0.05</it>). In suppressing the spread of tumor cells in mice, BNCT treatment was as effective with CG-HVJ-E-BSH as with BSH containing a 35-fold higher <sup>10</sup>B dose. Furthermore, CG-HVJ-E-BSH significantly increased the survival time of tumor-bearing mice compared to BSH at a comparable dosage of <sup>10</sup>B.</p> <p>Conclusion</p> <p>CG-HVJ-E-BSH is a promising strategy for the BNCT treatment of visceral tumors without severe adverse events to surrounding normal tissues.</p

    A Research on a New Science Curriculum Development Based on ‘Nature Of Science’ Ⅲ : Reconstruction of a Coherence Science Curriculum from Elementary School to Upper Secondary School

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    本研究は,新しい科学観を取り入れた小学校から高等学校までの理科カリキュラムを開発することを目的としており,今年度は3年次にあたる。これまでの成果と課題をもとに,初等・中等教育で一貫して「科学の本質」を学ぶためのフレームワーク構築に向け,小学校から高等学校を通じて系統的に取り扱うことが可能な内容について検討を行った。 中学校における実践からは,理科教師が,科学者コミュニティーによる知,政策決定者や教師たちによる教えるべき知,児童・生徒の発達段階や文脈などを考慮した教える知,について可能な限り熟知する必要があることが示唆された。また,論証活動を行う際の,教師の振る舞い方も重要であることも明らかとなった。 また,小学校における実践では,学年による差異はあるものの,見たことや考えたことの違いを次第に意識化させることによって,観察や実験等のレポートの書き方の指導にも繋がることが明らかとなった。 以上の実践より,科学の本質を初等・中等教育で一貫して教えるためには,これまでの実践の視点の変容に基づく教師による授業方略の在り方や投げ込み的教材を使用する教師の意図が,いかに重要であるかを示唆している。This study develops a new science curriculum for elementary to upper secondary schools which include the concept of the “Nature of Science”. We examined possible content to build a systematic framework for mentioned above science education. The practice at junior high school shows that teachers should be familiar with scholarly knowledge, knowledge to be taught by the policy makers and teachers, and taught knowledge which students understand through learning along with the students’ ages and contexts. The teacher’s behavior in argumentation by pupils is also important. The practice at elementary school shows that perceptions of the crucial distinction between inference and observation lead students to write good reports. These practices exemplify that teaching Nature of Science consistently to elementary and lower secondary students should largely depend on the teachers’ methods of instruction and what material they develop from a new viewpoint

    Effects of flexibility and entanglement of sodium hyaluronate in solutions on the entry flow in micro abrupt contraction-expansion channels

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    In this study, the effects of polymer flexibility and entanglement on elastic instability were investigated by observing sodium hyaluronate (hyaluronic acid sodium salt, Na-HA) solution in planar abrupt contraction-expansion microchannels. As the rigidity of Na-HA depends on the ionic strength of a solvent, Na-HA was dissolved in water and phosphate buffered saline with concentrations from 0.15 wt. % to 0.45 wt. %. The rheological properties were measured and analyzed to detect the Na-HA overlap and entanglement concentrations. The flow regimes of the Na-HA solutions in several planar abrupt contraction-expansion channels were characterized in the Reynolds number and Weissenberg number space. The effects of the solvent, solution concentration, and channel geometry on the elastic corner vortex growth curve and flow regimes characterized by the Weissenberg number were analyzed. It was found that the entanglement of Na-HA in the solution is a more dominant factor affecting the flow regimes than the solution relaxation time and polymer rigidity
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