140 research outputs found

    Accelerated induction of in vitro apatite formation by parallel alignment of hydrothermally oxidized titanium substrates separated by sub-millimeter gaps

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    Although autoclaving is a common sterilization method for biomedical devices, the ability to induce deposition of apatite particles on hydrothermally treated titanium is still not fully realized. This is because the induction ability is too weak to be evaluated via in vitro apatite formation in Kokubo's simulated body fluid (SBF) by the conventional immersion method, i.e. using samples with open and smooth surface. This study reports on the surface structure of hydrothermally treated titanium and the ability to induce deposition of apatite particles on the surface of parallel confined spaces separated by sub-millimeter gaps in Kokubo's SBF. Thin-film X-ray diffraction and analyses using Fourier transform infra-red (FT-IR) spectroscopy and Raman spectroscopy revealed that a nano-crystalline anatase-type titanium oxide layer was formed on titanium substrates after hydrothermal treatment at 150 degrees C for 2 h. When growth of the titanium oxide layer was moderately suppressed, the hydrothermally treated titanium surface exhibited a characteristic interference color, silver or gold, which does not impair the esthetic appearance of the titanium-based implant. The ability to induce deposition of apatite particles on hydrothermally treated titanium was remarkably amplified by parallel alignment of substrates separated by sub-millimeter gaps

    N-body simulation for self-gravitating collisional systems with a new SIMD instruction set extension to the x86 architecture, Advanced Vector eXtensions

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    We present a high-performance N-body code for self-gravitating collisional systems accelerated with the aid of a new SIMD instruction set extension of the x86 architecture: Advanced Vector eXtensions (AVX), an enhanced version of the Streaming SIMD Extensions (SSE). With one processor core of Intel Core i7-2600 processor (8 MB cache and 3.40 GHz) based on Sandy Bridge micro-architecture, we implemented a fourth-order Hermite scheme with individual timestep scheme (Makino and Aarseth, 1992), and achieved the performance of 20 giga floating point number operations per second (GFLOPS) for double-precision accuracy, which is two times and five times higher than that of the previously developed code implemented with the SSE instructions (Nitadori et al., 2006b), and that of a code implemented without any explicit use of SIMD instructions with the same processor core, respectively. We have parallelized the code by using so-called NINJA scheme (Nitadori et al., 2006a), and achieved 90 GFLOPS for a system containing more than N = 8192 particles with 8 MPI processes on four cores. We expect to achieve about 10 tera FLOPS (TFLOPS) for a self-gravitating collisional system with N 105 on massively parallel systems with at most 800 cores with Sandy Bridge micro-architecture. This performance will be comparable to that of Graphic Processing Unit (GPU) cluster systems, such as the one with about 200 Tesla C1070 GPUs (Spurzem et al., 2010). This paper offers an alternative to collisional N-body simulations with GRAPEs and GPUs.Comment: 14 pages, 9 figures, 3 tables, accepted for publication in New Astronomy. The code is publicly available at http://code.google.com/p/phantom-grape

    Relationship of tooth loss to mild memory impairment and cognitive impairment: findings from the fujiwara-kyo study

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    <p>Abstract</p> <p>Background</p> <p>This cross-sectional study investigated the relationship between the number of remaining teeth to mild memory impairment (MMI), which is a preclinical stage of dementia, and to cognitive impairment.</p> <p>Methods</p> <p>The subjects were aged 65 years or older and were grouped according to their score for the Mini-Mental State Examination (MMSE), the three-word delayed recall test in the MMSE, and the Geriatric Depression Scale into the control group (n = 3,696), the MMI group (n = 121), and the low MMSE score (23 or lower) group (n = 214). We collected data on the number of remaining teeth, the length of the edentulous period, health-related lifestyle, medical history, blood pressure, height, and body weight. Fasting venous blood samples were also obtained.</p> <p>Results</p> <p>Multiple logistic regression analysis, adjusted for depressive symptoms, age, sex, length of education, and other explanatory variables, revealed that the odds ratios of 0-10 remaining teeth to 22-32 remaining teeth were 1.679 (95% CI 1.073-2.627) for MMI and 2.177 (95% CI 1.510-3.140) for a low MMSE score. A significant relationship was also found between the length of the edentulous period and the risk of a low MMSE score (odds ratio 3.102, 95% CI 1.432-6.720) (15 years or more/less than 15 years).</p> <p>Conclusions</p> <p>Our findings suggest that tooth loss is associated with cognitive function.</p

    体の痛み、社会的支援、抑うつ状態、脳血管疾患は独立して高齢者の睡眠障害と関連する : 藤原京スタディ横断解析

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    OBJECTIVE: To investigate independent effects of various factors associated with sleep disturbance among community-dwelling elderly individuals. METHODS: We analyzed data obtained from 3732 individuals aged ≥65 years who responded to a self-administered questionnaire and participated in a structured interview which assessed the Pittsburgh Sleep Quality Index (PSQI), subjective bodily pain, the Jichi Medical School Social Support Scale, the Geriatric Depression Scale (GDS-15), health status, and demographic characteristics. Sleep disturbance was defined as a global PSQI score >5.5, which was used as a dependent variable in multiple logistic regression analysis to determine adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) of related factors. RESULTS: We identified a significant increase in the adjusted ORs for female (OR 1.56, 95 % CI 1.34-1.83), age ≥80 years (1.31, 1.01-1.69), history of stroke (1.44, 1.08-1.92), and a GDS-15 score ≥6 as compared to 0-2 (2.29, 1.86-2.81), with regard to sleep disturbance. Participants with severe or very severe bodily pain had the highest adjusted OR (3.00, 2.15-4.19), and those with very mild bodily pain also had a relatively high OR (1.30, 1.06-1.60), relative to those without subjective bodily pain. In addition, compared with participants with strong social support from spouse or family, those with weak social support had significantly increased adjusted ORs (1.21, 1.01-1.44, 1.44, 1.23-1.70, respectively). CONCLUSIONS: The present study indicates that sleeping disturbances among the elderly are closely associated with social support from a spouse and family. They are also associated with pain, even at stages in which subjective bodily pain is very mild.博士(医学)・乙第1381号・平成28年9月28日© The Japanese Society for Hygiene 2016The final publication is available at Springer via http://dx.doi.org/10.1007/s12199-016-0529-

    高齢者における日中光曝露が夜間尿中メラトニン分泌への与える影響 : 平城京スタディ横断解析

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    CONTEXT:Melatonin is involved in a variety of diseases, including cancer, insomnia, depression, dementia, hypertension, and diabetes; its secretion is influenced by environmental light. Although daylight exposure increases nocturnal melatonin secretion in a controlled laboratory setting, whether it increases nocturnal melatonin secretion in an uncontrolled daily life setting remains unclear.OBJECTIVE:We aimed to determine the association between daylight exposure in an uncontrolled daily life setting and urinary 6-sulfatoxymelatonin excretion.DESIGN AND PARTICIPANTS:A cross-sectional study was conducted in 192 elderly individuals (mean age, 69.9 yr).MEASURES:We measured ambulatory daylight exposure using a wrist light meter in two 48-h sessions; furthermore, we measured overnight urinary 6-sulfatoxymelatonin excretion, an index of melatonin secretion, on the second night of each session.RESULTS:The median duration of daylight exposure of at least 1000 lux was 72 min (interquartile range, 37-124). Univariate linear regression analysis showed marginal to significant associations between log-transformed urinary 6-sulfatoxymelatonin excretion and age, current smoking status, benzodiazepine use, day length, log-transformed duration of daylight exposure of at least 1000 lux, and daytime physical activity. In a multivariate model, log-transformed duration of daylight exposure of at least 1000 lux was significantly associated with log-transformed urinary 6-sulfatoxymelatonin excretion (regression coefficient, 0.101; 95% confidence interval, 0.003-0.199; P = 0.043). Furthermore, an increase in the duration of daylight exposure of at least 1000 lux from 37 to 124 min (25th to 75th percentiles) was associated with a 13.0% increase in urinary 6-sulfatoxymelatonin excretion (6.8 to 7.7 μg).CONCLUSIONS:Daylight exposure in an uncontrolled daily life setting is positively associated with urinary 6-sulfatoxymelatonin excretion in the elderly.博士(医学)・乙第1308号・平成25年3月15日Copyright © 2012 by The Endocrine Societ

    高齢者の手段的ADL低下に対するスポーツと文化的趣味活動の交互作用-藤原京スタディー

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    Background: Maintenance of instrumental activities of daily living (IADL) and social role (SR) is crucial to keep independent life because the decline in SR and IADL was a significant predictor of dependence in basic ADL in later. The independent effect of physical and cultural leisure activities and their effect modification on the IADL remains unknown. Methods: We prospectively observed 3241 elderly with intact IADL at baseline for 5 years. Higher level functional capacity such as IADL and SR was assessed using the Tokyo Metropolitan Institute of Gerontology Index of competence (TMIG index). Results: The mean age of the participants was 72.3 years (standard deviation 5.1), and 46.9% were male, and 90.9% of them received a follow-up assessment. Of the participants, 10.4% developed an IADL decline. Engagement in leisure physical activity was associated with a significantly lower risk of IADL decline (adjusted risk ratio, 0.73; 95% confidence interval [CI], 0.60 to 0.89), and cultural leisure activity was also associated with lower risk of IADL decline (adjusted risk ratio, 0.77; 95% CI, 0.63 to 0.95) independent of potential confounders. We also found significant and positive interaction between physical and cultural leisure activities at risk for IADL decline (P = 0.024) and SR decline (P = 0.004). Conclusions: We found an independent association of physical and cultural leisure activities with a lower risk for functional decline in IADL and SR with positive interaction. Combined engagement in physical and cultural activities may effectively prevent from IADL decline and SR decline.博士(医学)・乙第1456号・令和2年3月16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

    A reliable fistula closure technique for refractory pneumothorax unresponsive to pleurodesis.

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    An 86-year-old man, who had undergone pleurodesis several times for intractable pneumothorax due to severe emphysema was referred to our department in order to treat for recurrent pneumothorax. Computed tomography after chest tube drainage revealed incomplete re-expansion right lung and giant cyst. Because the air leakage continued, we performed surgery. Thoracotomy revealed extensive intrathoracic adhesions due to chemical pleurodesis with OK-432. There was a fistula at the base of the giant cyst in the upper right lobe, which was firmly adhered to the superior vena cava and other mediastinal organs. It was not feasible to staple the lesion cyst, and covering the fistula was ineffective. Therefore, we tried to suture the fragile bulla manually to close the fistula. Adhesion was peeled off carefully to relieve tension of the bulla from mediastinum. The thin wall was folded and reinforced with polytetrafluoroethylene pledget, and then this thickened tissue was sutured to the lung with U-stitches to close the fistula. After the operation, pneumothorax improved. He was discharged without complications
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