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81.
We report the case of a 66-year-old man suffering from Werner's syndrome (adult progeria); he presented with several cardiac disorders, including coronary artery disease, aortic stenosis, and mitral regurgitation, mainly due to calcific deposits in the mitral annulus and the aortic cusps. Treatment consisted of mitral repair, homograft replacement of the aortic valve, and coronary artery bypass grafting. Avoidance of prosthetic material because of chronic infectious skin ulcers constituted the main goal of the operation.  相似文献   
82.
The microporous material Ionsiv is used for 137Cs removal from aqueous nuclear waste streams. In the UK, Cs-loaded Ionsiv is classed as an intermediate-level waste; no sentencing and disposal route is yet defined for this material and it is currently held in safe interim storage on several nuclear sites. In this study, the suitability of fly ash and blast furnace slag blended cements for encapsulation of Cs-Ionsiv in a monolithic wasteform was investigated. No evidence of reaction or dissolution of the Cs-Ionsiv in the cementitious environment was found by scanning electron microscopy and X-ray diffraction. However, a small fraction (≤ 1.6 wt.%) of the Cs inventory was released from the encapsulated Ionsiv during leaching experiments carried out on hydrated samples. Furthermore, it was evident that K and Na present in the cementitious pore water exchanged with Cs and H in the Ionsiv. Therefore, cement systems lower in K and Na, such as slag based cements, showed lower Cs release than the fly ash based cements.  相似文献   
83.
Improvements on winding flux models for a slotless self-bearing motor   总被引:1,自引:0,他引:1  
For a large-scale slotless permanent-magnet self-bearing motor actuator, finite-element analysis (FEA) indicates a significant difference from the previous simple winding flux model. In this paper, we first derive a general winding current distribution. We use and compare three analytical methods to calculate the air gap field produced by the windings when only torque is required. Each of the first two solves one homogeneous Laplace's equation with the current source incorporated into a harmonic boundary condition, in polar and Cartesian coordinates, respectively. The good agreement between these two allows the third method to treat the current source separately and solve one nonhomogeneous and one homogeneous Laplace's equations simultaneously in two subregions, simply using the unwrapped geometry in Cartesian coordinates. The result from the two-layer model matches the FEA prediction for this particular actuator very well and it is thus more accurate to model the thick windings as a separate source layer. We propose a simple approach to include the interference of the magnetic fields due to the segment currents whenever a bearing force is required, which was completely neglected in all the previous models. The approach is quite accurate, as shown by the corresponding FEA result.  相似文献   
84.
Neural Computing and Applications - In human communication, facial expressions play an important role, which carries enough information about human emotions. Last two decades, it becomes a very...  相似文献   
85.
Although the cryogenic and electronic problems of a large lead/liquid argon shower system such as in the Mark II require considerable attention to detail during design, construction, and set-up, the performance of a large system equals that of small test systems and agrees well with reasonable expectations. The shower detector system of the Mark II has been mechanically, cryogenically, and electronically very reliable during eighteen months of normal operation at SPEAR. Performance has provided a good compromise among the various demands upon shower detection. The system has enabled physics measurements previously untenable to other e+e- detectors.  相似文献   
86.
Silicon Carbide (SiC) is a wide bandgap semiconductor material that offers performance improvements over Si for power semiconductors with accompanying benefits for power electronics applications that use these semiconductors. The wide bandgap of SiC results in higher junction forward voltage drops, so SiC is best suited for majority carrier devices such as field effect transistors (FETs) and Schottky diodes. The wide bandgap of SiC results in it having a high breakdown electric field, which in turn results in lower resistivity and narrower drift regions in power devices. This dramatically lowers the resistance of the drift region and means that SiC devices with substantially less area than their corresponding Si devices can be used. The lower device area reduces the capacitance of the devices enabling higher frequency operation. Here, the results from a 1-MHz hard-switched dc-dc converter employing SiC JFETs and Schottky diodes will be presented. This converter was designed to convert 270Vdc to 42Vdc such as may be needed in future electric cars. The results provide the performance obtained at 1MHz and demonstrate the feasibility of a hard-switched dc-dc converter operating at this frequency.  相似文献   
87.
Wildfire fighters are known to report to work in a hypohydrated state, which may compromise their work performance and health.  相似文献   
88.
Switched reluctance motor (SRM) performance prediction requires the modeling of iron losses. The iron loss model in this paper separates the iron losses into two components, eddy-current and hysteresis losses, and models the losses as a function of the derivative of flux density. The model is suitable for the nonsinusoidal flux densities in the SRM and predicts the iron losses as a function of time. The model is general and can be applied to any electromagnetic device with known geometry and material property. The equations of iron loss are verified and validated through experiments with two simple geometries (a transformer and a toroid) and two SRMs.  相似文献   
89.
We examined the association between sleep behavior and cognitive functioning in 60 healthy children between 7 and 11 years of age under nonexperimental conditions. Intellectual abilities were assessed by the Wechsler Intelligence Scale for Children (4th edition) and sleep variables by questionnaires, actigraphy, and sleep diaries. Correlation analysis revealed a negative association between sleep duration on weekends and measures of intelligence (full-scale IQ, r = ?.29; fluid IQ, r = ?.36). The regression coefficient for sleep duration on weekends was ?6.11 (SE = 2.09), indicating an increase of 6.11 points on fluid IQ scores for each hour of shorter sleep duration. Attention measures did not correlate with cognitive or sleep variables. Daytime sleepiness as a potential moderator of the relationship between sleep duration and cognitive performance was not related to cognitive or sleep variables. We conclude that children with higher daytime cognitive efficiency (reflected by higher intelligence scores) show increased nighttime efficiency (reflected by shorter sleep duration). In the light of the neural efficiency hypothesis, the current results argue for an extension of the original theory—referring not only to daytime but also to nighttime behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
90.

Scope

Modifying the composition of colostrum by external factors may provide opportunities to improve the infant's health. Here, we evaluated how fish oil and/or probiotics supplementation modify concentrations of colostrum immune mediators and their associations with perinatal clinical factors on mothers with overweight/obesity.

Methods and results

Pregnant women were randomized in a double-blind manner into four intervention groups, and the supplements were consumed daily from early pregnancy onwards. Colostrum samples were collected from 187 mothers, and 16 immune mediators were measured using bead-based immunoassays. Interventions modified colostrum composition; the fish oil+probiotics group had higher concentrations of IL-12p70 than probiotics+placebo and higher FMS-like tyrosine kinase 3 ligand (FLT-3L) than fish oil+placebo and probiotics+placebo (one-way analysis of variance, post-hoc Tukey's test). Although the fish oil+probiotics group had higher levels of IFNα2 compared to the fish oil+placebo group, these differences were not statistically significant after correction for multiple testing. Multivariate linear model revealed significant associations between several immune mediators and the perinatal use of medication.

Conclusion

Fish oil/probiotics intervention exerted a minor effect on concentrations of colostrum immune mediators. However, medication during the perinatal period modulated the immune mediators. These changes in colostrum's composition may contribute to immune system development in the infant.  相似文献   
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