M.P. belt deterioration. Accelerator structure. Belt capability

An explanation to the M.P. belt deterioration is proposed. It takes into account the strain of discharge to which the belt is submitted following the combination, first of a too high belt charge density in addition to the machine voltage contribution, second the geometrical configuration of the gradient rods which induces an inhomogeneous field and allows the belt to reach too high voltages not compatible with the particular Paschen curve. This explanation leads to define the concept of belt charge capability. The field configuration critical for a certain charge density also exists in other places. Different simple solutions are proposed to cure this problem and allow the M.P. belt to operate under normal electrical conditions

Leukodystrophies: clinical and therapeutic aspects

This chapter reviews that leukodystrophies is a genetic diseases that occur in early childhood. It is a possibility that leads to screening for leukodystrophy patients with early-onset dementia of unknown origin or atypical psychiatric symptoms. The chapter focuses on genetic cases of white matter involvement presenting with deficits in cognitive functions or dementia. Leukodystrophies are rare causes of dementia in the adult. They may cause a dementia of the frontal type or psychiatric symptoms than can mimic schizophrenia but are rapidly associated with long tract involvement. The presence of other cases in the family is a crucial step in the diagnosis but apparently isolated cases are frequent. Homochrony and homotypy are the rule but with many exceptions they have to be considered for genetic counseling. MRI is also critical, showing abnormal increased signals of the white matter on T2-weighted and FLAIR sequences, with a frontal predominance. Normal MRI imaging, at least at the beginning of the disease, does not rule out the diagnosis. The study of the pathogenetic mechanisms of leukodystrophies has been improved by the development and the analysis of animal models. The chapter states that no curative treatment is yet available. New perspectives have opened with the development of cell and gene therapies, even in adult forms, where the demyelination can at least be stabilized

Belt charging system

In M.P. accelerators belts have encountered some difficulties mainly about the belt life time. In the belt charging system, parameters are investigated and some of them are pointed out as being partly responsible either for belt deterioration or for belt ripple. Experiments are and will be carried out to surround the actual belt limitations

Non – Hodgkin’s Lymphoma presenting as Garcin’s Syndrome – A case report and Literature Review

An 80 year old man presented with a twelve month history of progressive multiple unilateral cranial nerve palsies. A gadolinium enhanced MRI scan of his head and neck was performed. This showed an extra-axial enhancing lesion, which enveloped the hemi-mandible at the level of the left inferior alveolar nerve, and a dumbbell shaped lesion within the cerebellopontine angle. An incisional biopsy was performed to gain a tissue diagnosis, which demonstrated a Non-Hodgkin’s Lymphoma. The combination of signs, symptoms and radiological findings enabled a diagnosis of Garcin’s Syndrome secondary to Non-Hodgkin’s Lymphoma

Développement d’un outil de simulation numérique basé sur l’approche "Weak-Scatterer" pour l’étude des systèmes houlomoteurs en grands mouvements

Usual numerical tools for designing floating bodies have shown their limits when considering WEC’s conception. Codes based on linear potential theory and boundary value problems are fast but limited to low amplitude of motions around mean positions. On contrary, wave energy converters efficiency relies on large amplitude of motions. An alternative approach onsists in linearizing the perturbations on the incident wave position (Weak-Scatterer approach) while the body conditions are expressed on the body exact position. Sea-keeping studies of wave energy converters with this method may give results with a better precision in reasonable computational time. Thus this thesis consists in developing a numerical tool based on this approach and comparing its benefits with the state of the art linearized one. This code is based on the potential theory using Rankine sources in timedomain, revisited according to the conception choices.The analytical expressions of the integral equations were thus written for a linear discretization. The boundary value problem for the time derivative of the velocity potential was also entirely re-developed, to validate the different existing expressions and provide a new simplified one. This theoretical developments were implemented into modules, which were validated usingreference solutions. An application case was performed to evaluate the performances of a wave energy converter, consisting in a heaving submerged buoy.Les codes de tenue à la mer basés sur la résolution d'un problème aux limites en théorie potentielle linéarisée, largement utilisée pour l'étude des systèmes flottants conventionnels pour leurs faibles temps de calcul, sont limités par définition à de faibles amplitudes de mouvement. L'efficacité des systèmes houlomoteurs repose, au contraire, sur de grands mouvements: ces systèmes doivent ainsi être conçus avec des fréquences de résonance proches des fréquences de houle. Cette condition est aux antipodes des hypothèses fondamentales des codes potentiels linéaires. Une approche alternative consiste à linéariser les perturbations autour de la déformée de houle incidente (approche Weak-Scatterer) et à exprimer les conditions de glissement sur la position exacte du corps. Ce formalisme doit ainsi pouvoir permettre de traiter avec une meilleure précision les problèmes de tenue à la mer de système houlomoteurs en grands mouvements, tout en maintenant des temps de calculs raisonnables.Ce travail de thèse consiste en le développement d’un code basé sur cette approche et son exploitation afind’évaluer ses avantages par rapport à l’approche complètement linéarisée de l’état de l’art. Ce code temporel est basé sur la théorie potentielle avec des sources de Rankine, revisitée selon les choix de conception. Les expressions analytiques des équations intégrales ont ainsi été développées pour une discrétisation linéaire des grandeurs. De même, la détermination de la dérivée temporelle du potentiel par résolution d'un problème aux limites a été complètement reprise pour valider les différentes expressions existantes et donner naissance à une nouvelle, simplifiée. Ces développements théoriques ont été implémentés au sein de différents modules du code, qui ont été successivement validés à l'aide de solutions de référence analytiques ou numériques. L'exploitation du code a finalement permis d'évaluer les performancesd'un système houlomoteur de type bouée pilonnante immergée

Photo-responsive polymer with erasable and reconfigurable micro- and nano-patterns: An in vitro study for neuron guidance

The interaction of cells with nanoscale topography has proven to be an important modality in controlling cell responses. Topographic parameters on material surfaces play a role in cell growth. We have synthesized a new bio compatible polymer containing photoswitching molecules. Stripepatterned (groove/ridge pattern) were patterned and erased with ease on this bio azopolymer with two different set-ups: one with the projection of an optical interference pattern and the other one by molecular self-organization with one single laser beam. These two set-ups allow the re-writing of pattern after erasing and its inscription in vitro. PC12 cells were cultured on the bio-photoswitching patterned polymer and compared with PC12 cells growing on a well know substrate: poly-L-lysine. This result is of interest for facilitating contact guidance and designing reconfigurable scaffold for neural network formation in vitro. (C) 2011 Elsevier B.V. All rights reserve

Efficient extraction of resonant states in systems with defects

We introduce a new numerical method to compute resonances induced by localized defects in crystals. This method solves an integral equation in the defect region to compute analytic continuations of resolvents. Such an approach enables one to express the resonance in terms of a "resonance source", a function that is strictly localized within the defect region. The kernel of the integral equation, to be applied on such a source term, is the Green function of the perfect crystal, which we show can be computed efficiently by a complex deformation of the Brillouin zone, named Brillouin Complex Deformation (BCD), thereby extending to reciprocal space the concept of complex coordinate transformations

Neuropathie démyélinisante au cours d’un traitement par anti-TNF alpha et revue de la littérature

Introduction Tumor necrosis factor- (TNF) blockers are efficient in the treatment of autoimmune disorders such as inflammatory bowel disease and rheumatoid arthritis, but can induce CNS adverse effects including retrobulbar optic neuritis or aggravation of multiple sclerosis. Observation We report a case of progressive demyelinating polyneuropathy after initiation of Adalimumab (Humira®). Corticosteroid and intravenous immunoglobulins were ineffective but the neuropathy improved within six months after adalimunab discontinuation. Discussion This case, and other reports recently published suggest that anti-TNF alpha drugs can induce demyelinating neuropathy. Conclusion Clinicians should be on the lookout for signs evocating neuropathy in patients given anti TNF alpha

Stable tubule only polypeptides (STOP) proteins co-aggregate with spheroid neurofilaments in amyotrophic lateral sclerosis

A major cytopathological hallmark of amyotrophic lateral sclerosis (ALS) is the presence of axonal spheroids containing abnormally accumulated neurofilaments. The mechanism of their formation, their contribution to the disease, and the possibility of other co-aggregated components are still enigmatic. Here we analyze the composition of such lesions with special reference to stable tubule only polypeptide (STOP), a protein responsible for microtubule cold stabilization. In normal human brain and spinal cord, the distribution of STOP proteins is uniform between the cytoplasm and neurites of neurons. However, all the neurofilament-rich spheroids present in the tissues of affected patients are intensely labeled with 3 different anti-STOP antibodies. Moreover, when neurofilaments and microtubules are isolated from spinal cord and brain, STOP proteins are systematically co-purified with neurofilaments. By SDS-PAGE analysis, no alteration of the migration profile of STOP proteins is observed in pathological samples. Other microtubular proteins, like tubulin or kinesin, are inconstantly present in spheroids, suggesting that a microtubule destabilizing process may be involved in the pathogenesis of ALS. These results indicate that the selective co-aggregation of neurofilament and STOP proteins represent a new cytopathological marker for spheroids

Osteochondral impaction of the posterior acetabular surface without cortical fracture of any wall or column: an undescribed pattern of acetabular injury

Surgical treatment of a unusual acetabular fracture is described. This fracture was characterized by impaction and breaking down of the posterior articular surface and comminution of lamina quadrilatera lower portion, without cortical fracture of both columns. The fracture was treated surgically through the Kocher–Langenbeck approach. A small hole was created in the acetabulum posterior wall, the impacted fragment was reduced, and the bone defect was filled with autologous bone from the greater trochanter. A plate was shaped in order to fix both bone graft and fractured fragment