2,891 research outputs found
Effects of Fe2O3 addition on the nitridation of silicon powder
The reaction of silicon powder and nitrogen was studied in the range of 1300-1400 C. When an addition of Fe2O3 was more than 0.8wt%, the reaction was linear and compared to samples with no Fe2O3, the reaction velocity increased 5 to 10 times. The reactions were mediated by the process of peeling and cracking in a thin layer of Si2N4 formed on the silicon particles or on the surface of the Fe-Si melts. As the addition of Fe2O3 increased, the reaction activation energy for highly pure samples decreased. Fe2O3 which exceeded the Si3N4 solubility limits was finally converted to d-Fe
Significance of myocardial tenascin-C expression in left ventricular remodelling and long-term outcome in patients with dilated cardiomyopathy
Aim Dilated cardiomyopathy (DCM) has a variety of causes, and no useful approach to predict left ventricular (LV) remodelling and long-term outcome has yet been established. Myocardial tenascin-C (TNC) is known to appear under pathological conditions, possibly to regulate cardiac remodelling. The aim of this study was to clarify the significance of myocardial TNC expression in LV remodelling and the long-term outcome in DCM. Methods and results One hundred and twenty-three consecutive DCM patients who underwent endomyocardial biopsy for initial diagnosis were studied. Expression of TNC in biopsy sections was analysed immunohistochemically to quantify the ratio of the TNC-positive area to the whole myocardial tissue area (TNC area). Clinical parameters associated with TNC area were investigated. The patients were divided into two groups based on receiver operating characteristic analysis of TNC area to predict death: high TNC group with TNC area ≥2.3% (22 patients) and low TNC group with TNC area <2.3% (101 patients). High TNC was associated with diabetes mellitus. Comparing echocardiographic findings between before and 9 months after endomyocardial biopsy, the low TNC group was associated with decreased LV end-diastolic diameter and increased LV ejection fraction, whereas the high TNC group was not. Survival analysis revealed a worse outcome in the high TNC group than in the low TNC group (P < 0.001). Multivariable Cox regression analysis revealed that TNC area was independently associated with poor outcome (HR = 1.347, P = 0.032). Conclusions Increased myocardial TNC expression was associated with worse LV remodeling and long-term outcome in DCM
Production and Chemical Separation of “No Carrier Added" Iodine-124 from a Reusable Enriched Tellurium-124 Dioxide / Aluminum Oxide Solid Solution Target
Development of a Pulse Height Estimation Method for a High Resolution PET Camera with Position Sensitive Semiconductor Detectors
On the induced gauge invariant mass
We derive a general expression for the gauge invariant mass (m_G) for an
Abelian gauge field, as induced by vacuum polarization, in 1+1 dimensions. From
its relation to the chiral anomaly, we show that m_G has to satisfy a certain
quantization condition. This quantization can be, on the other hand, explicitly
verified by using the exact general expression for the gauge invariant mass in
terms of the fermion propagator. This result is applied to some explicit
examples, exploring the possibility of having interesting physical situations
where the value of departs from its canonical value. We also study the
possibility of generalizing the results to the 2+1 dimensional case at finite
temperature, showing that there are indeed situations where a finite and
non-vanishing gauge invariant mass is induced.Comment: 18 pages, Latex, 3 figures (pstex
Impact of Dental Diseases on Quality-Adjusted Life Expectancy in US Adults
Comparing the burden of dental conditions to other health outcomes provides useful insight for public policy. We aimed to estimate quality-adjusted life expectancy (QALE) loss due to dental conditions in the US adult population. Social inequalities in QALE loss by dental conditions were also examined. Data from 3 cross-sectional waves of the National Health and Nutrition Examination Survey (NHANES waves 2001 to 2002, 2003 to 2004, and 2011 to 2012) were pooled and analyzed. The average age of study participants (n = 9,445) was 48.4 y. Disutility scores were derived from self-rated health and the numbers of physically unhealthy days, mentally unhealthy days, and days with activity limitation, employing a previously published algorithm. The associations between the disutility scores and the numbers of decayed teeth, missing teeth, and periodontitis were examined by multiple linear regression stratified by age groups (20–39, 40–59, and ≥60 y), adjusted for other covariates (age, sex, wave fixed effect, educational attainment, smoking, and diabetes). The QALE loss due to dental conditions at the age of 20 was estimated using life tables. Decayed and missing teeth, but not periodontitis, were associated with a larger disutility score. The coefficient for decayed teeth was larger among the older population, whereas that of missing teeth was smaller among them. The estimated QALE loss was 0.43 y (95% confidence interval [CI], 0.28–0.59), which reached 5.3% of QALE loss (8.15 y; 95% CI, 8.03–8.27) due to overall morbidity. There were clear social gradients in QALE loss by dental conditions across the life course, and people with high school or less education had 0.32 y larger QALE loss in total compared with people with college or more education. This study suggests that improvements in people’s dental health may yield substantial gains in population health and well-being. The necessity of more comprehensive public health strategies is highlighted
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