52 research outputs found
Morphological differences in Parkinson's disease with and without rest tremor
Background : Rest tremor is a hallmark of Parkinson's disease (PD), but its pathogenesis remains incompletely understood. Nigro-striatal dopamine deficiency correlates best with bradykinesia, but not with tremor. Oscillating neurons in one or multiple localizations within the basal gangliathalamo-cortical loop may cause rest tremor, and an active contribution of the cerebellum and the cerebello-thalamo-cortical projections has been postulated. Objective : To compare the pattern of grey matter volume in PD patients with and without tremor to identify structural correlates of rest tremor. Methods : Voxel-based morphometry (VBM) of a high-resolution 3 Tesla, T1-weighted MR images, pre-processed according to an optimized protocol using SPM2, was performed in 24 patients with mild to moderate PD comparing local grey matter volume in patients with (n = 14) and without rest tremor (n = 10). Results : Grey matter volume is decreased in the right quadrangular lobe and declive of the cerebellum in PD with tremor compared to those without (PFDR < 0.05). Conclusions : These results demonstrate for the first time morphological changes in the cerebellum in PD patients with rest tremor and highlight the involvement of the cerebellum and cerebello- thalamo-cortical circuit in the pathogenesis of parkinsonian rest tremo
Изготовление изделий сложной формы из металлических порошков методом квазиизостатического прессования
Работа посвящена изучению влияния параметров эластичной оболочки (жесткость,объем внутренней полости) на деформацию металлических порошковых материалов в процессе квазиизостатического прессования.The work is devoted to the study of the influence of the parameters of the elastic shell (stiffness, volume of the internal cavity) on the deformation of metal powder materials in the process of quasi-isostatic pressing
Tunable two-dimensional electron system at the (110) surface of SnO
We report the observation of a two-dimensional electron system (2DES) at the
surface of the transparent bulk insulator SnO, and the tunability
of its carrier density by means of temperature or Eu deposition. The 2DES is
insensitive to surface reconstructions and, surprisingly, it survives even
after exposure to ambient conditions --an extraordinary fact recalling the well
known catalytic properties SnO. Our data show that surface oxygen vacancies
are at the origin of such 2DES, providing key information about the
long-debated origin of -type conductivity in SnO, at the basis of a wide
range of applications. Furthermore, our study shows that the emergence of a
2DES in a given oxide depends on a delicate interplay between its crystal
structure and the orbital character of its conduction band.Comment: 11 pages, 12 figure
Cerebral perfusion in sepsis
This article is one of ten reviews selected from the Yearbook of Intensive Care and Emergency Medicine 2010 (Springer Verlag) and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/yearbook. Further information about the Yearbook of Intensive Care and Emergency Medicine is available from http://www.springer.com/series/2855
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