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Multimedia Tools and Applications - Studies of visual attention of patients with Dementia such as Parkinson’s Disease Dementia and Alzheimer Disease is a promising way for non-invasive...  相似文献   
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A systematic review of the neurologic literature identified 433 cases of pathologically proven multiple system atrophy over a 100-year period. Earlier case reports included patients younger in age with more frequent cerebellar involvement. Mean age of onset was 54.2 years (range 31 to 78) and survival was 6.2 years (range 0.5 to 24). Survival analysis showed a secular trend from a median duration of 4.9 years for publications between 1887 and 1970 to 6.8 years between 1991 and 1994. Older age of onset was associated with shorter survival; the hazard ratio for patients with onset after 60 years was 1.8 (95% CI 1.4 to 2.3) compared with patients between 31 and 49 years. Cerebellar features were associated with marginally increased survival (6.1 years versus 5.4 years; p = 0.04). There were no difference in survival according to gender, parkinsonian, or pyramidal features or whether the patient was classified as striatonigral degeneration or olivopontocerebellar atrophy type. These results demonstrate the poor prognosis for patients with multiple system atrophy but may be biased toward the worst cases. Future research needs to recruit more representative samples.  相似文献   
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The prevalence of specific thrombotic accidents recognized in 260 patients with thrombocytosis are reported. Ninety one were affected by PV, 86 by ET, 20 by MF and 63 by ST. The highest incidence of thrombosis was in the PV group. About half of ET and MF patients experienced a thrombosis. In all the patients thrombosis preferentially affected the cerebrovascular district (17.3% of the cases). Coronary artery disease occurred in PV while peripheral vascular disease was frequent in ET. Portal vein district thrombosis is not rare during the course of all MPD (7.1%). Apparently, deep vein thrombosis occurs in all patients with both primary and secondary thrombocytosis.  相似文献   
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Stolojan V  Tison Y  Chen GY  Silva R 《Nano letters》2006,6(9):1837-1841
The growth of carbon nanotubes from Ni catalysts is reversed and observed in real time in a transmission electron microscope, at room temperature. The Ni catalyst is found to be Ni3C and remains attached to the nanotube throughout the irradiation sequence, indicating that C most likely diffuses on the surface of the catalyst to form nanotubes. We calculate the energy barrier for saturating the Ni3C (2-13) surface with C to be 0.14 eV, thus providing a low-energy surface for the formation of graphene planes.  相似文献   
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The various chromatographic methods suitable for the separation and quantitative determination of phenoxyalkyl acid herbicides in environmental samples are reviewed, with special emphasis being placed on sample preparation methods such as liquid-liquid, solid-phase and supercritical fluid extractions. Techniques are classified (high-performance liquid chromatography, gas-liquid chromatography, capillary zone electrophoresis, micellar electrokinetic chromatography) and discussed separately. The advantages and disadvantages of the various preparation and separation methods and their combinations are evaluated.  相似文献   
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The aim of this paper is to propose an algorithm to decide the confluence of finite ground term rewrite systems. Actually a more general class of possibly infinite ground term rewrite systems is studied. It is well known that the confluence is not decidable for general term rewrite systems, but this paper proves it is for ground term rewrite systems following a conjecture made by Huet and Oppen in their survey. The result is also applied to the confluence of left-linear and right-ground term rewrite systems. We also sketch an algorithm for checking this property. This algorithm is based on tree automata and tree transducers. Here, we regard them as rewrite systems and specialists in automata theory would translate that easily in their language.  相似文献   
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Giusca CE  Tison Y  Silva SR 《Nano letters》2008,8(10):3350-3356
The atomic and electronic structure of a twisted and collapsed double-walled carbon nanotube was characterized using scanning tunneling microscopy and spectroscopy. It was found that the deformation opens an electronic band gap in an otherwise metallic nanotube, which has major ramifications on the use of carbon nanotubes for electronic applications. Fundamentally, the importance of the intershell interaction in this double-walled carbon nanotube points to the potential of a reversible metal-semiconductor junction, which can have device applications, as well as a caution in the design of semiconductor components based on carbon nanotubes. Lattice registry effects between the two neighboring walls evidenced by atomically resolved images confirm earlier first principle calculations indicating that the helicity influences the collapsed structure and show excellent agreement with the predicted twisted-collapse mode.  相似文献   
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