In this letter, a lightning observation camera system and an observation result are represented. The system consists of a slow-speed CCTV camera, a consumer high-speed digital camera EXILIM EX-F1S and a personal computer for controlling the camera system. Its total cost is a fraction of standard high-speed cameras used for the lightning observation. Observation of downward lightning strokes to the top of TOKYO SKYTREE was succeeded by the camera system.

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Lightning hits to Tokyo Skytree have been under observation by a high-speed camera since August 2012. First data were obtained when negative downward lightning flashes hit the tower on July 08, 2013. This letter reports on observation of a negative single-stroke flash with a positive upward leader initiated from Tokyo Skytree extended about 400m before connection with a downward leader. Simultaneously observed electric field observed by a fast antenna showed much weaker stepped-leader pulses compared to ordinary negative downward flashes hitting ground.

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Titanium oxide whisker reinforced aluminum matrix composites were fabricated by a powder metallurgical method. Our previous study on tensile properties of TiO₂(N)/A1 composite indicated that the interfacial reaction occured considerably on the fabrication process, however, their tensile properties were nearly equal with those of SiC(W)/ Al composite.
In this study, fatigue strength was examined by rotating bending test, and the whisker /matrix interface structure was investigated by scanning electron microscope and X-ray diffraction method. For the TiO₂(w)/A1 composite, TiO₂ whisker changed to Ti₂O₃ after hot pressing and A1, Ti and A1₂O₃ were produced after hot extrusion at the interfaces. Fatigue limit for the TiO₂(R)/A1 composite increased about 50% compared with that of monolithic aluminum. Fatigue crack growth direction was diflected by the whisker and propagated in the matrix along the interface. This fact means that the resistance to crack initiation and propagation increased because the adhesion force between whisker and matrix was improved by the existence of reactants at the interface.

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TOKYO SKYTREE^® has recently been constructed in the eastern area of central Tokyo, located in the Kanto Plain, and is the tallest free-standing broadcasting tower in the world (634m). To observe the current waveshapes of lightning striking TOKYO SKYTREE^®, the authors have installed Rogowski coils on the tower at a height of 497m. In this letter, the authors report on the lightning current waveshapes observed at TOKYO SKYTREE^®.

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Lightning observation has been carried out at Tokyo Skytree, which is a 634-m high freestanding broadcasting tower located in a flat terrain at 1m ASL. 25 downward and 37 upward flashes were observed at the tower during 2012 to 2016. This paper focuses on upward negative flashes initiated from the top of the tower. Of the 37 confirmed upward flashes, 35 current waveforms were recorded by Rogowski coils installed at 497-m height of the tower. One out of 35 upward flashes was a positive flash initiated by a negative upward leader, 7 out of 35 flashes were bipolar flashes initiated by positive upward leaders, and the rest were negative flashes initiated by positive upward leaders. The authors evaluated the lightning current parameters of subsequent strokes and initial continuous currents (ICC) of the upward negative flashes.

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最近, 高血圧患者には, 高頻度に耐糖能異常を合併することが報告されている. 同時に高血圧, 耐糖能異常はいずれも加齢の影響を強く受けることも知られている. そこで本研究においては,人間ドックを受診した576人を対象に, 日本人における高血圧患者と耐糖能異常の相互関係を解析するとともに, 対象患者を50歳未満・50～60歳まで・60歳以上の3群に分類して両者の関係に及ぼす加齢の影響についても検討した. 50歳以下の若年者では, 日本人においても欧米人と同様, 高血圧患者の耐糖能異常の頻度は正常血圧者に比し有意に高頻度であった. 一方, 50歳台では両群間に有意の差は見られなかった. 60歳以上の老年群では, 高血圧群で耐糖能異常を合併しやすい傾向を示した. また, 75g-OGTTで耐糖能正常と判定された症例においても, 高血圧群では正常血圧群に比し, いずれの年齢層においても, 血糖増加面積が高い傾向を示していたことより, 高血圧群は正常血圧群より耐糖能の低下を来たしていることが示された. 以上の結果より, 耐糖能正常者についてみると, 高齢群・青壮年群いずれにおいても, 高血圧の耐糖能に及ぼす影響が観察されるが, 糖尿病・IGTといった耐糖能異常に関してみると, 正常者のIGT・糖尿病への移行には, 高血圧よりも加齢の方がより強い影響を及ぼしており, このため, 加齢の影響を考慮しなくてよい青壮年者においてのみ高血圧の耐糖能に及ぼす影響が認められると考えられる.

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Recently, various kinds of oxide whisker have been developed which are much cheaper than SiC or Si₃N₄ whiskers. These oxide whiskers may be available for fillers which reinforce metal matrix composites. We have already studied on the microstructural change at interface and tensile properties of oxide whiskers reinforced aluminum and aluminum alloy matrices composites. The results were that aluminum borate whisker reinforced composite revealed the most superior specific strength and the most stable microstructure of all. The aim of this study was to make clear the fatigue behavior of the composite comparing with SiC whisker reinforced one. Fatigue limits were increased with volume fraction like that of SiC whisker reinforced one, however, the dependence of whisker volume fraction on fatigue strength was weaker than that for SiC whisker reinforced one. This difference was considered to be due to smaller aspect ratio of aluminum borate whisker which decreased more than that of SiC whisker with increasing whisker volume fraction.

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症例は58歳男性.交通事故で破裂腸管切除を受け,その際中心静脈カテーテルを挿入された.抜去2カ月後刺入部を中心とする発赤腫脹が出現し,鎖骨骨髄炎の診断で入院,鎖骨内側および胸骨を一部切除掻爬し治癒した.中心静脈カテーテル挿入に起因する合併症の中で鎖骨骨髄炎は,きわめて稀な合併症で内外の報告を併せてもわずかに7症例である.発症の原因としては,カテーテル挿入時の骨膜損傷または周囲の血腫形成が最も重要であり,ここに血行性または刺入部皮膚から直接細菌が侵入生着すると考えられる.予防的には,無菌法の実施と穿刺手技の向上はいうまでもないが,近年安易に行われる傾向にある中心静脈カテーテルの適応基準を厳格にし,末梢静脈で管理できる症例には適用とすべきではない.鎖骨骨髄炎の頻度は低いが,治療に当たっては抗生剤による治療に拘泥すると敗血症を併発して死亡する報告もあり,手術の時機を逸しないように注意すべきである.

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