311 research outputs found

    Nonlinear Absorption by Porphyrin Supramolecules

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    Development of the dynamic motion simulator of 3D micro-gravity with a combined passive/active suspension system

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    The establishment of those in-orbit operations like 'Rendez-Vous/Docking' and 'Manipulator Berthing' with the assistance of robotics or autonomous control technology, is essential for the near future space programs. In order to study the control methods, develop the flight models, and verify how the system works, we need a tool or a testbed which enables us to simulate mechanically the micro-gravity environment. There have been many attempts to develop the micro-gravity testbeds, but once the simulation goes into the docking and berthing operation that involves mechanical contacts among multi bodies, the requirement becomes critical. A group at the Tokyo Institute of Technology has proposed a method that can simulate the 3D micro-gravity producing a smooth response to the impact phenomena with relatively simple apparatus. Recently the group carried out basic experiments successfully using a prototype hardware model of the testbed. This paper will present our idea of the 3D micro-gravity simulator and report the results of our initial experiments

    Attempt to Generate Uniform Magnetic Field by Face-to-Face Magnet System Containing HTS Bulk Magnets

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    In order to develop small-scale nuclear magnetic resonance devices, the authors have been developing uniform magnetic fields in the space between the face-to-face settled magnetic poles which contain HTS bulk magnets. Since the NMR magnets in general require highly uniform field, it was expected to be difficult to form such homogeneous magnetic-field distribution with use of HTS bulk magnet, because the bulk magnets is characterized by its inhomogeneous magnetic field showing steep gradient. The authors modified the shape of the field distribution from convex to concave by attaching an iron plate on the pole surface. Then, the magnets were then settled face-to-face with various gaps, and the magnetic-field uniformity was estimated in the space. In order to detect the NMR signals, the field uniformity less than 1,500 ppm should be required after the former results on the hollow-type magnets. When we combined the concave and convex field distributions to compensate the uneven field distributions, the best uniformity reached 358 ppm in the 30 mm gaps, which exceeded the target value. In addition, we numerically simulated the feasible performance in this configuration, which resulted in obtaining the best uniformity of 30 ppm at 1.1 T at 7 mm distant from the pole surface in the gap of 30 mm. This result suggested that the concave and convex magnetic field distributions compensate the field uniformity with each other with keeping the magnetic field strength in the gap

    Lysophosphatidic Acid Induces Allergic Inflammation

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    Background: Lysophosphatidic acid (LPA), a prototypic member of a large family of lysophospholipids, has been recently shown to play a role in immune responses to respiratory diseases. The involvement of LPA in allergic airway inflammation has been reported, but the mechanism remains unclear. Object: We analyzed the biological activity of LPA in vitro and in vivo and investigated its role in allergic inflammation in mice using an LPA receptor 2 (LPA2) antagonist. Methods: We used a murine model with acute allergic inflammation, in which mice are sensitized and challenged with house dust mite, and analyzed airway hyperresponsiveness (AHR), pathological findings, Th2 cytokines, and IL-33 in bronchoalveolar lavage fluid (BALF) and lung homogenates. The effect of LPA on Th2 differentiation and cytokine production was examined in vitro using naive CD4+ T cells isolated from splenocytes. We also investigated in vivo the effects of LPA on intranasal administration in mice. Results: The LPA2 antagonist suppressed the increase of AHR, the number of total cells, and eosinophils in BALF and lung tissue. It also decreased the production of IL-13 in BALF and IL-33 and CCL2 in the lung. LPA promoted Th2 cell differentiation and IL-13 production by Th2 cells in vitro. Nasal administration of LPA significantly increased the number of total cells and IL-13 in BALF via regulating the production of IL-33 and CCL-2-derived infiltrating macrophages. Conclusion: These findings suggest that LPA plays an important role in allergic airway inflammation and that the blockade of LPA2 might have therapeutic potential for bronchial asthma

    Can computed tomography differentiate adenocarcinoma in situ from minimally invasive adenocarcinoma?

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    Background: Given the subtle pathological signs of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), effective differentiation between the two entities is crucial. However, it is difficult to predict these conditions using preoperative computed tomography (CT) imaging. In this study, we investigated whether histological diagnosis of AIS and MIA using quantitative three-dimensional CT imaging analysis could be predicted. Methods: We retrospectively analyzed the images and histopathological findings of patients with lung cancer who were diagnosed with AIS or MIA between January 2017 and June 2018. We used Synapse Vincent (v. 4.3) (Fujifilm) software to analyze the CT attenuation values and performed a histogram analysis. Results: There were 22 patients with AIS and 22 with MIA. The ground-glass nodule (GGN) rate was significantly higher in patients with AIS (p < 0.001), whereas the solid volume (p < 0.001) and solid rate (p = 0.001) were significantly higher in those with MIA. The mean (p = 0.002) and maximum (p = 0.025) CT values were significantly higher in patients with MIA. The 25th, 50th, 75th, and 97.5th percentiles (all p < 0.05) for the CT values were significantly higher in patients with MIA. Conclusions: We demonstrated that quantitative analysis of 3D-CT imaging data using software can help distinguish AIS from MIA. These analyses are useful for guiding decision-making in the surgical management of early lung cancer, as well as subsequent follow-up

    人工靭帯へのケイ酸ストロンチウムアパタイトナノコートは骨形成を促進する

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    Background: Treatment of anterior cruciate ligament injuries commonly involves the use of polyethylene terephthalate (PET) artificial ligaments for reconstruction. However, the currently available methods require long fixation periods, thereby necessitating the development of alternative methods to accelerate the healing process between tendons and bones. Thus, we developed and evaluated a novel technique that utilizes silicate-substituted strontium (SrSiP). Methods: PET films, nano-coated with SrSiP, were prepared. Bone marrow mesenchymal cells (BMSCs) from femurs of male rats were cultured and seeded at a density of 1.0 × 104/cm2 onto the SrSiP-coated and non-coated PET film, and subsequently placed in an osteogenic medium. The osteocalcin concentration secreted into the medium was compared in each case. Next, PET artificial ligament, nano-coated with SrSiP, were prepared. BMSCs were seeded at a density of 4.5 × 105/cm2 onto the SrSiP-coated, and non-coated artificial ligament, and then placed in osteogenic medium. The osteocalcin and calcium concentrations in the culture medium were measured on the 8th, 10th, 12th, and 14th day of culture. Furthermore, mRNA expression of osteocalcin, alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP2), and runt-related transcription factor 2 (Runx2) was evaluated by qPCR. We transplanted the SrSiP-coated and non-coated artificial ligament to the tibiae of mature New Zealand white rabbits. Two months later, we sacrificed them and histologically evaluated them. Results: The secretory osteocalcin concentration in the medium on the film was significantly higher for the SrSiP group than for the non-coated group. Secretory osteocalcin concentration in the medium on the artificial ligament was also significantly higher in the SrSiP group than in the non-coated group on the 14th day. Calcium concentration on the artificial ligament was significantly lower in the SrSiP group than in the non-coated group on the 8th, 10th, 12th, and 14th day. In qPCR as well, OC, ALP, BMP2, and Runx2 mRNA expression were significantly higher in the SrSiP group than in the non-coated group. Newly formed bone was histologically found around the artificial ligament in the SrSiP group. Conclusions: Our findings demonstrate that artificial ligaments using SrSiP display high osteogenic potential and thus may be efficiently used in future clinical applications.博士(医学)・甲第724号・令和元年12月5日© The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

    High revivability of vitrified-warmed bovine mature oocytes after recovery culture with alpha-tocopherol

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    online publication: 27 January 2015The objective of this study was to investigate whether developmental competence of vitrified–warmed bovine oocytes can be improved by antioxidant treatment during recovery culture. In experiment 1, one of the two antioxidants (either l-ascorbic acid or α-tocopherol) was added as a supplement to the recovery culture medium to which postwarming oocytes were exposed for 2 h before IVF. The exposure to α-tocopherol had a positive effect on rescuing the oocytes as assessed by the blastocyst yield 8 days after the IVF (35.1–36.3% vs 19.2–25.8% in untreated postwarming oocytes). Quality of expanding blastocysts harvested on Day 8 was comparable between α-tocopherol-treated vitrification group and fresh control group in terms of total cell number and chromosomal ploidy. In experiment 2, level of reactive oxygen species, mitochondrial activity, and distribution of cortical granules in α-tocopherol-treated postwarming oocytes were assessed. No obvious differences from the control data were found in these parameters. However, the treatment with α-tocopherol increased the percentage of zygotes exhibiting normal single aster formation (90.3% vs 48.0% in untreated postwarming oocytes; 10 h post-IVF). It was concluded that α-tocopherol treatment of vitrified–warmed bovine mature oocytes during recovery culture can improve their revivability, as shown by the high blastocyst yield and the higher mean total cell number in the blastocysts.ArticleREPRODUCTION. 149(4):347-355 (2015)journal articl

    Attempt to Generate a Strong and Uniform Magnetic Field by Face-to-face HTS Bulk Elements in a Magnet System

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    AbstractA unique experimental attempt aiming to obtain a uniform magnetic field space as required for NMR has been carried out with use of HTS bulk magnets. The magnetic poles were activated as 1.8 T (North) and 1.4 T (South) at 30K by applyinga pulsed magnetic field up to 7 T, and positioned face-to-face with gaps less than 70mm. The uniformity of the magnetic field required for detecting the NMR signals isless than 1,500ppm at more than 0.3 T in the cross sectional plane of 2 x 2 mm2. After thepreliminary trials whichrevealed auniformity of 5,421ppm at 0.44 T in a70mm gap, we attached a ferromagnetic iron plate to a magnetic pole surface to change the magnetic field distribution to be concave. The best uniformity of 358ppm at 1.11 T was obtained at 9mm distance from the iron plate surface in a gap of 30mm. It is stated that the concave magnetic field distribution was compensated by the counter conical-shape field, resulting in the uniform field plane
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