130 research outputs found

    Propagation of light beams along line defects formed in a-Si/SiO2 three-dimensional photonic crystals: Fabrication and observation

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    科研費報告書収録論文(課題番号:09650339・基盤研究(C)(2)・H9~H10/研究代表者:花泉, 修/ファイバ集積型マイクロ光スイッチの作製とメカニズムの解明

    Recent Progress of Aluminum Base Amorphous Alloys

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    During the past three decades, there have been considerable efforts on the production of an amorphous phase in Al base alloy systems and in 1987 the first successful data on the formation of an amorphous alloy with good ductility have been presented in Al-Ni-(Si or Ge) systems. Al base amorphous alloys have been reported to exhibit technologically interesting properties of high fracture strength combined with low density and good corrosion resistance as well as a scientifically important glass transition phenomenon. This review attempts to summarize the fundamental data on the Al base amorphous alloys consisting of metal-metalloid and metal-metal type components and to present the present interpretation on formation, structure and physical properties of the Al-based amorphous alloys

    Impact of efforts to prevent maternal deaths due to obstetric hemorrhage on trends in epidemiology and management of severe postpartum hemorrhage in Japan: a nationwide retrospective study

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    BACKGROUND: The Japan Society of Obstetrics and Gynecology and the Japan Association of Obstetricians and Gynecologists have issued the guidelines and recommendations on postpartum hemorrhage since 2010 and have been conducted widespread educational activities from 2012. The aim of this study was to investigate the impact of these efforts by the Societies to prevent maternal deaths due to obstetric hemorrhage on trends in epidemiology and management of severe postpartum hemorrhage in Japan. METHODS: A national retrospective cohort study was conducted using the national database of health insurance claims for the period 2012 and 2018. The subjects were all insured women who received a blood transfusion for postpartum hemorrhage. The primary endpoints of this study were hysterectomy and maternal mortality. The etiology of hemorrhage, treatment facility, type of procedure, and blood transfusion volume were tabulated. RESULTS: Women with postpartum hemorrhage that underwent transfusion increased from 3.5 to 5.5 per 1000 deliveries between 2012 and 2018. The most common cause of postpartum hemorrhage was atonic hemorrhage. After insurance coverage in 2013, the intrauterine balloon tamponade use increased to 20.3% of postpartum hemorrhages treated with transfusion in 2018, while the proportion of hysterectomy was decreased from 7.6% (2013-2015) to 6.4% (2016-2018) (p < 0.0001). The proportion of postpartum hemorrhage in maternal deaths decreased from 21.1% (2013-2015) to 14.1% (2016-2018) per all maternal deaths cases (p = 0.14). Cases with postpartum hemorrhage managed in large referral hospitals was increased (65.9% in 2012 to 70.4% in 2018) during the study period (p < 0.0001). CONCLUSIONS: The efforts by the Societies to prevent maternal mortality due to obstetric hemorrhage resulted in a significant decrease in the frequency of hysterectomies and a downward trend in maternal mortality due to obstetric hemorrhage

    Trend of anticoagulant therapy in elderly patients with atrial fibrillation considering risks of cerebral infarction and bleeding

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    The introduction of direct oral anticoagulants (DOACs) has greatly changed the use of anticoagulant therapy in patients with non-valvular atrial fibrillation (Af). Therefore, this study aimed to examine changes in the proportions of oral anticoagulant prescriptions in patients with non-valvular Af aged ≥ 65 years, taking into consideration the risk of cerebral infarction and bleeding. Anticoagulant prescriptions in outpatients aged ≥ 65 years with Af were temporally analyzed using the nationwide claims database in Japan. Trends in anticoagulant prescriptions were examined according to cerebral infarction and bleeding risk. The proportion of anticoagulant prescriptions for 12, 076 Af patients increased from 41% in 2011 to 56% in 2015. An increase in DOAC prescriptions was accompanied by an increase in the proportion of anticoagulant prescriptions in each group according to the CHA2DS2-VASc and HAS-BLED scores. The proportion of anticoagulant prescriptions for patients with a high risk of developing cerebral infarction and bleeding showed a marked increase. Trends in anticoagulant prescriptions in Af patient with a CHA2DS2-VASc score ≥ 2 and HAS-BLED scores ≥ 3 showed a marked increase in DOAC prescriptions. The widespread use of DOACs greatly changes the profile the prescription of anticoagulant therapy in patients with Af

    重症低血糖後の急性冠症候群の絶対リスク : 日本のナショナルデータベースを用いた一般集団対象の2年間のコホート研究

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    Aims/introduction: Although the epidemiological relationship between hypoglycemia and increased risk of acute coronary syndrome (ACS) has been well established, the time period for increased risk of ACS after a severe hypoglycemic episode remains unknown. The present study aimed to determine the ACS risk after a severe hypoglycemic episode. Materials and methods: We carried out a retrospective population-based cohort study based on national claims data in Japan. We retrieved data of diabetes patients aged ≥35 years collected from April 2014 to March 2016. The absolute risk of ACS was defined as the occurrence of an emergency percutaneous coronary intervention after a severe hypoglycemic episode. Results: In total, data of 7,909,626 patients were included in the analysis. The absolute risk of ACS was 2.9 out of 1,000 person-years in all patients. ACS risk in patients with severe hypoglycemic episodes was 3.0 out of 1,000 person-years. Severe hypoglycemic episodes increased the absolute risk of ACS in patients aged ≥70 years, but not in patients aged <70 years. The absolute risk of ACS was 10.6 out of 1,000 person-years within 10 days of a severe hypoglycemic episode. There was a significant trend between shorter duration after an episode and higher ACS risk. Conclusions: Severe hypoglycemia was associated with an increased risk of ACS in elderly diabetes patients. ACS risk increased with a shorter period after a severe hypoglycemic episode, suggesting that severe hypoglycemia leads to an increased risk of ACS in diabetes patients. These findings show that it is important to avoid severe hypoglycemia while treating diabetes, particularly in elderly patients.博士(医学)・甲第732号・令和2年3月16日© 2019 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License(https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made

    Incidence of central serous chorioretinopathy (2011–2018): a nationwide population-based cohort study of Japan

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    国の診療報酬請求データベースを用いて特殊な網膜剥離の発症率を明らかに --NDBオンサイトリサーチセンター(京都)を活用した初の成果--. 京都大学プレスリリース. 2021-07-19.[Aims] The aim of this study was to elucidate the epidemiological background of central serous chorioretinopathy (CSC), including its incidence and treatment pattern. [Methods] This was a population-based longitudinal cohort study using a nationwide health insurance claims database of the Japan Ministry of Health, Labour and Welfare (MHLW). As Japan employs universal health coverage, the database covers more than 95% of claims issued in Japan. We accessed all data stored in the database with permission from the MHLW. We traced all individuals aged 30 years or older and identified individuals with new onset of CSC between January 2011 and December 2018. CSC cases were categorised by age and sex for each year, and incidence rate was calculated. We also identified major treatments for CSC to elucidate the initial treatment pattern. [Results] During the 8-year period, 247 930 incidences of CSC were identified, among which 75.9% were men. The crude incidence rate (per 100 000 person-years) in the general population aged 30 years or older was 34.0 (95% CI 33.9 to 34.2), in men was 54.2 (95% CI 53.9 to 54.4) and in women was 15.7 (95% CI 15.5 to 15.8). The mean age of onset was lower in men than in women (50.5±12.5 years vs 54.7±13.5 years). Most of the patients with newly diagnosed CSC (86.8%) did not receive major treatment. [Conclusions] The current study provides the nationwide population-based evidence to clarify the detailed epidemiology of CSC. These results could help to understand the pathogenesis and mechanisms of CSC in the future
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