91 research outputs found

    Long Rayleigh length confocal microscope: A fast evaluation tool for obtaining quantum properties of color centers

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    Color centers in wide band-gap semiconductors, which have superior quantum properties even at room temperature and atmospheric pressure, have been actively applied to quantum sensing devices. Characterization of the quantum properties of the color centers in the semiconductor materials and ensuring that these properties are uniform over a wide area are key issues for developing quantum sensing devices based on color center. In this article, we will describe the principle and performance of a newly developed confocal microscope system with a long Rayleigh length (LRCFM). This system can characterize a wider area faster than the confocal microscope systems commonly used for color center evaluation

    Clearance and Safety of the Radiocontrast Medium Iopamidol in Peritoneal Dialysis Patients

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    Although the characteristics and safety of radiocontrast media in peritoneal dialysis (PD) patients are not yet well defined, their use in PD patients is considered generally safe. In this study, we evaluated clearance and adverse events of iopamidol in PD patients. We measured the iopamidol concentration in the plasma, dialysate, and urine of 11 patients. Iopamidol clearance from patient plasma was delayed with a half-life of 33.3 h, and the elimination ratio was 83.6% for 96 h. We retrospectively investigated adverse events occurring in a total of 50 stable PD patients who underwent a total of 64 angiographic computed tomography (CT) scans. In 64 angiographic CT scans, two cases of adverse events were observed. Our results suggest that iopamidol can be eliminated by regular PD and careful observation for adverse events are necessary for the safe use of radiocontrast media

    コウトウ キョウイク カイカク ノ ソウゴ コウイ ブンセキ : ビデオ エスノグラフィー ケンキュウ ノ ネライ ト コウガクブ トシ コウガク エンシュウ ノ ジッサイ

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    ビデオエスノグラフィーは、当事者的知識を十分に摂取しながら行うビデオ分析であり、我々は この方法で、高等教育改革の現場を研究した。生涯学習社会の到来を受けて、日本の高等教育は現在第 2 次世界大戦直後以来の改革期にある。すなわち、「知識」より「生涯学習能力」の獲得を志向した、 自発性を尊重するような様々な取り組みがなされ始めている。この高等教育の現場に対し、ワークプレ ース研究を行った。B大学工学部都市工学演習α班を分析対象とした調査の結果、①演習の課題解釈に は「従来の指標の相対化の要求の程度」を巡って2つの解釈があり得たこと、②班内にはその2種類の 解釈に対応した葛藤・対立的相互行為が存在したこと、③にもかかわらず、班内葛藤を生きる当事者が ともに専門性(「都市工学」)を志向していたこと、④したがって、課題理解のいかんにかかわらず、 班活動の全体が「都市工学演習」と呼び得るものになっていたこと、⑤その一方で、最終審査会場(ジ ュリー)ではこの2重性が十分レリバントなものとして浮かび上がって来ていなかったこと、これらの ことがわかった。諸結果を総合すると、学生の自主的活動を尊重するタイプの、新しい学習方法の吟味・ 評価のためには、学生によるその方法の実践状況の分析が有意義であるだろうこと、また、それは、場 合によっては教員の評価のパラダイムを変える力を持つだろうことなどが予測された。なお、本報告は、 文科省科学研究費補助金「高等教育改革のコミュニケーション分析-現場における文化変容の質的検討 -」(基盤研究(B)、 課題番号 18330105、研究代表者:樫田美雄)ほかによる研究成果 の一部である

    Nucleation and growth of biomimetic apatite layers on 3D plotted biodegradable polymeric scaffolds : effect of static and dynamic coating conditions

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    Apatite layers were grown on the surface of newly developed starch/polycaprolactone (SPCL)-based scaffolds by a 3D plotting technology. To produce the biomimetic coatings, a sodium silicate gel was used as nucleating agent, followed by immersion in a simulated body fluid (SBF) solution. After growing a stable apatite layer for 7 days, the scaffolds were placed in SBF under static, agitated (80 strokes min!1) and circulating flow perfusion (Q = 4 ml min!1; tR = 15 s) for up to 14 days. The materials were characterized by scanning electron microscopy/energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and thin-film X-ray diffraction. Cross-sections were obtained and the coating thickness was measured. The elemental composition of solution and coatings was monitored by inductively coupled plasma spectroscopy. After only 6 h of immersion in SBF it was possible to observe the formation of small nuclei of an amorphous calcium phosphate (ACP) layer. After subsequent SBF immersion from 7 to 14 days under static, agitated and circulating flow perfusion conditions, these layers grew into bone-like nanocrystalline carbonated apatites covering each scaffold fiber without compromising its initial morphology. No differences in the apatite composition/chemical structure were detectable between the coating conditions. In case of flow perfusion, the coating thickness was significantly higher. This condition, besides mimicking better the biological milieu, allowed for the coating of complex architectures at higher rates, which can greatly reduce the coating step.The authors acknowledge the Portuguese Foundation for Science and Technology (PhD grant to A.L.O., SFRH/BD/10956/2002 and post-doctoral Grant to R.A.S., SFRH/BPD/17151/2004, under the POCTI Program). This work was partially supported by FCT through POCTI and/or FEDER programmes and also partially supported by the EU Project HIPPOCRATES (NMP3-CT-2003-505758) and EXPERTISSUES (NMP-CT-2004-500283)

    Long-term exposure to microgravity impairs vestibulo-cardiovascular reflex

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    The vestibular system is known to have an important role in controlling blood pressure upon posture transition (vestibulo-cardiovascular reflex, VCR). However, under a different gravitational environment, the sensitivity of the vestibular system may be altered. Thus, the VCR may become less sensitive after spaceflight because of orthostatic intolerance potentially induced by long-term exposure to microgravity. To test this hypothesis in humans, we investigated the ability of the VCR to maintain blood pressure upon head-up tilt before and after a 4–6 months stay on the International Space Station. To detect the functional state of the VCR, galvanic vestibular stimulation (GVS) was applied. As GVS transiently interrupts the vestibular-mediated pressor response, impaired VCR is detected when the head-up tilt-induced blood pressure response does not depend on GVS. During the first 20 s of head-up tilt, a transient blood pressure increase (11.9 ± 1.6 mmHg) was observed at pre-spaceflight but not at 1–4 days after return from spaceflight. The magnitude of VCR recovered to the pre-spaceflight levels within 2 months after return. These results indicate that long-term exposure to microgravity induces VCR impairment, which may be involved in a mechanism of spaceflight-induced orthostatic intolerance

    TOC, CaCO3, n-alkane and alkenone concentrations of ODP Sites 202-1237 and 202-1239

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    We generated preliminary downcore records of total organic carbon content, calcium carbonate, long-chain n-alkane concentration, total alkenone concentration, and alkenone-based sea-surface temperature for samples from the easternmost flank of Nazca Ridge (Site 1237) and the eastern crest of Carnegie Ridge (Site 1239). Total organic carbon and long-chain n-alkane concentrations will be used to evaluate terrestrial sediment sources. Downcore records of alkenone sea-surface temperature will benefit studies of paleoceanography of the southeastern Pacific. Since these sites are located under the influence of major tectonic events, such as the uplift of the Andes Mountains and the closure of the Isthmus of Panama, the records will help us to examine the effects of the tectonic events on the oceanic environment
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