72 research outputs found
Comparison of prognostic scores and surgical approaches to treat spinal metastatic tumors: A review of 57 cases
Surgical treatment of metastatic spinal cord compression with or without neural deficit is controversial. Karnofsky and Tokuhashi scores have been proposed for prognosis of spinal metastasis. Here, we conducted a retrospective analysis of Karnofsky and modified Tokuhashi scores in 57 consecutive patients undergoing surgery for secondary spinal metastases to evaluate the value of these scores in aiding decision making for surgery. Comparison of preoperative Karnofsky and modified Tokuhashi scores with the type of the surgical approach for each patient revealed that both scores not only reliably estimate life expectancy, but also objectively improved surgical decisions. When the general status of the patient is poor (i.e., Karnofsky score less than 40% or modified Tokuhashi score of 5 or greater), palliative treatments and radiotherapy, rather than surgery, should be considered
Structural insights into the contactin 1 - neurofascin 155 adhesion complex
Cell-surface expressed contactin 1 and neurofascin 155 control wiring of the nervous system and interact across cells to form and maintain paranodal myelin-axon junctions. The molecular mechanism of contactin 1 - neurofascin 155 adhesion complex formation is unresolved. Crystallographic structures of complexed and individual contactin 1 and neurofascin 155 binding regions presented here, provide a rich picture of how competing and complementary interfaces, post-translational glycosylation, splice differences and structural plasticity enable formation of diverse adhesion sites. Structural, biophysical, and cell-clustering analysis reveal how conserved Ig1-2 interfaces form competing heterophilic contactin 1 - neurofascin 155 and homophilic neurofascin 155 complexes whereas contactin 1 forms low-affinity clusters through interfaces on Ig3-6. The structures explain how the heterophilic Ig1-Ig4 horseshoe's in the contactin 1 - neurofascin 155 complex define the 7.4 nm paranodal spacing and how the remaining six domains enable bridging of distinct intercellular distances
Kinetic Resolution of Chiral a-Olefins Using Optically Active ansa-Zirconocene Polymerization Catalysts
Surgery in spinal metastasis without spinal cord compression: indications and strategy related to the risk of recurrence
Godedzor, a Late-Ubaid-related settlement in Southern Caucasus
Pubblicazione dei risultati delle prime campagne di scavo del sito di Godedzor in Armenia. Godedzor è un sito stagionale probabilmente occupato da gruppi di pastori transumanti provenineti dall'Iran che giocano un ruolo centrale nella circolazione dell'ossidiana in Iran Nord-Occidentale nel corso del IV millennio a. C
Spinal cord compression complicating aseptic spondylodiscitis in ankylosing spondylitis.
International audienceAseptic spondylodiscitis is a well recognized complication of ankylosing spondylitis. Neurological complications of such discovertebral lesions are uncommon. We report a new case with a diagnosis of T12-L1 spondylodiscitis which developed ten years after a spinal cord compression. Such neurological complications of aseptic spondylodiscitis may be explained by proliferative epidural tissue without predominant inflammatory infiltrates and also the development of new bone reaction, suggesting the contribution of mechanical factors
Assessment of the rotational stiffness of single-riveted joints in a steel lattice girder by modal analysis
Abstract: Wrought-iron and mild-steel riveted lattice girders are widespread structural components of the French metallic construction heritage of 1850\u20131930. Many rafters and purlins of roof structures of train sheds or market halls are made of flat and angle bars assembled with single-riveted joints. The assessment of the mechanical properties of those joints is key to sensitive and targeted retrofitting operations. Despite its influence on the buckling risk of lattice girders, the out-of-plane rotational stiffness of the joints has not been investigated yet. To fill this gap, experimental and numerical investigations based on modal analysis techniques were carried out on a riveted steel lattice girder dating from 1930. The measured natural frequencies and mode shapes were used to update a finite-element model of the girder. The results suggest that the single-riveted joints exhibit a rigid behaviour in the out-of-plane direction. When numerically varying the rotational joint stiffness, two indicators seem to be relevant, one based on the study of mode shapes, and the other one linked to the presence of additional numerical modes compared to the experimental measurements. Furthermore, a numerical study was conducted to assess the potential use of the findings to develop a modal-based damage detection method for riveted joints. With only one measurement point on each lattice web member, an indicator named ECOMAC, derived from the enhanced coordinate modal assurance criterion (ECOMAC) proposed in the literature, appears capable of detecting and localising one or several joints presenting a loss of stiffness. Overall, this paper shows that experimental modal analysis can be an efficient tool for assessing single-riveted joints in old steel lattice girders
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