220 research outputs found

    マウスガードの自律神経活動への影響 : 瞳孔フラッシュ応答による定量的評価

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    Background:Recently, it has been reported that mouth guards (MGs), which reduce the incidence and severity of traumatic oral injuries in contact sports, may actually affect sports performance. We have observed that a majority of subjects showed improved dynamic visual acuity during head rotation when using a MG, but subjects who were unwilling to use a MG showed the opposite effect. Thus, we hypothesized that unpleasant sensations due to MGs may decrease sports performance.Methods:In this study, we measured autonomic nervous system activity to evaluate unpleasant sensations objectively and quantitatively by measuring the pupillary flash response (PFR) and heart rate variability (HRV), before, during, and after wearing 3- and 5-mm-thick custom-made MGs in 10 healthy subjects.Results:It was found that the 5-mm MG had a higher incidence of unpleasant sensations (50% of subjects) than did the 3-mm MG (10%). PFR (not HRV) analysis showed that both sympathetic and parasympathetic nervous system activities increased in subjects with unpleasant sensations.Conclusions:We suggest that the unpleasant sensation induced this unusual autonomic nervous system response, which could not be detected by traditional methods such as HRV analysis. By using PFR analysis, it is possible to make MGs without unpleasant sensations for better sports performance.博士(医学)・乙第1306号・平成24年11月27日Copyright © 2012 Japanese Stomatological Society. Published by Elsevier Japan K

    Extreme Lobbyists and Policy Convergence

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    We consider a two-candidate election model with campaign contributions. In the first stage of the game, each of two candidates chooses a policy position. In the second stage, each of n lobbyists chooses the amount of contribution to each candidate. The winning probability of each candidate depends on the total amount of contributions that she raised from the lobbyists. In any equilibrium of our model, only extreme lobbyists contribute at any subgame, and the policies converge on the unique equilibrium path. Our results suggest that extreme lobbyists and their contributions do not necessarily cause policies to diverge.41 p

    Boulder size and shape distributions on asteroid Ryugu

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    In 2018, the Japanese spacecraft Hayabusa2, arrived at the small asteroid Ryugu. The surface of this C-type asteroid is covered with numerous boulders whose size and shape distributions are investigated in this study. Using a few hundred Optical Navigation Camera (ONC) images with a pixel scale of approximately 0.65 m, we focus on boulders greater than 5m in diameter. Smaller boulders are also considered using five arbitrarily chosen ONC close-up images with pixel scales ranging from 0.7 to 6 cm. Across the entire surface area (~2.7 km2) of Ryugu, nearly 4400 boulders larger than 5m were identified. Boulders appear to be uniformly distributed across the entire surface, with some slight differences in latitude and longitude. At ~50 km−2, the number density of boulders larger than 20m is twice as large as on asteroid Itokawa (or Bennu). The apparent shapes of Ryugu's boulders resemble laboratory impact fragments, with larger boulders being more elongated. The ratio of the total volume of boulders larger than 5m to the total excavated volume of craters larger than 20m on Ryugu can be estimated to be ~94%, which is comparatively high. These observations strongly support the hypothesis that most boulders found on Ryugu resulted from the catastrophic disruption of Ryugu's larger parent body, as described in previous papers (Watanabe et al., 2019; Sugita et al.,2019). The cumulative size distribution of boulders larger than 5 m has a power-index of −2.65 ± 0.05, which is comparatively shallow compared with other asteroids visited by spacecraft. For boulders smaller than 4 m, the power-index is even shallower and ranges from −1.65 ± 0.05 to −2.01 ± 0.06. This particularly shallow power-index implies that some boulders are buried in Ryugu's regolith. Based on our observations, we suggest that boulders near the equator might have been buried by the migration of finer material and, as a result, the number density of boulders larger than 5 m in the equatorial region is lower than at higher latitudes

    Aortic Dissection in a Patient with Human Immunodeficiency Virus Infection That was Diagnosed at Autopsy : A Case Report.

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    A 43-year-old homosexual man was referred to our hospital for chest pain and loss of consciousness. He was hypertensive, and had an uncontrolled viral load. Serum creatinine revealed acute renal failure, and he died 3 days later. On autopsy, aortic dissection (TypeB) was found. No obvious inflammatory change, granulation, bacterial or fungal infection, or medionecrosis were seen at the dissection site. To our knowledge, this was the first case with HIV in whom aortic dissection was diagnosed at autopsy. Aortic dissection is a potential differential diagnosis even in young patients presenting with hypertension and chest pain

    Annual report by The Japanese Association for Thoracic Surgery

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    All data regarding cardiovascular surgery and thoracic surgery were obtained from NCD, whereas data regarding esophageal surgery were collected from survey questionnaire by The Japanese Association for Thoracic Surgery forms because NCD of esophageal surgery does not include non-surgical cases (i.e., patients with adjuvant chemotherapy or radiation alone). Based on the change in data aggregation, there are several differences between this 2015 annual report and previous annual reports: the number of institutions decreased in each category from 578 (2014) to 568 (2015) in cardiovascular, from 762 to 714 in general thoracic and from 626 to 571 in esophageal surgery. Because more than two departments in the same institute registered their data to NCD individually, we cannot calculate correct number of institutes in this survey. Then, the response rate is not indicated in the category of cardiovascular surgery (Table 1), and the number of institutions classified by the operation number is also not calculated in the category of cardiovascular surgery (Table 2)

    Administration of Bone Marrow-Derived Mononuclear Cells Contributed to the Reduction of Hypoxic-Ischemic Brain Injury in Neonatal Rats

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    Background/Objective: Perinatal hypoxic-ischemia (HI) causes neonatal death and permanent neurological deficits. Cell therapy using various cell sources has been recently identified as a novel therapy for perinatal HI. Among the available types of cell sources, bone marrow-derived mononuclear cells (BMMNCs) have unique features for clinical application. For example, stem cells can be collected after admission, thus enabling us to perform autologous transplantation. This study aimed to investigate whether the administration of BMMNCs ameliorated HI brain injury in a neonatal rat model.Methods: Seven-day-old rats underwent left carotid artery ligation and were exposed to 8% oxygen for 60 min. BMMNCs were collected from the femurs and tibias of juvenile rats using the Ficoll–Hypaque technique and injected intravenously 24 h after the insult (1 × 105 cells). Active caspase-3, as an apoptosis marker, and ED1, as an activated microglia/macrophage marker, were evaluated immunohistochemically 48 h after the insult (vehicle, n = 9; BMMNC, n = 10). Behavioral assessments using the rotarod treadmill, gait analysis, and active avoidance tests were initiated 3 weeks after the insult (sham, n = 9, vehicle, n = 8; BMMNC, n = 8). After these behavioral tests (6 weeks after the insult), we evaluated the volumes of their hippocampi, cortices, thalami, striata, and globus pallidus.Results: The mean cell densities of the sum of four parts that were positive for active caspase-3 significantly decreased in the BMMNC group (p < 0.05), whereas in the hippocampi, cortices, thalami, and striata cell densities decreased by 42, 60, 56, and 47%, respectively, although statistical significance was not attained. The number of ED1 positive cells for the sum of the four parts also significantly decreased in the BMMNC group compared to the vehicle group (p < 0.05), whereas in each of the four parts the decrease was 35, 39, 47, and 36%, respectively, although statistical significance was not attained. In gait analysis, the BMMNC normalized the contact area of the affected hind paw widened by HI. The volumes of the affected striata and globus pallidus were significantly larger in the BMMNC group than in the control group.Conclusion: These results indicated that the injection of BMMNCs ameliorated HI brain injury in a neonatal rat model
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