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The production of composites, using waste materials as matrix and reinforcement, is an innovative, environmentally relevant, and economically viable alternative, regarding the environmental problems generated by inappropriate disposal. This study aimed to produce and characterize the technological properties of composites based on low-density polyethylene produced by extrusion with proportions of 0, 10, 20, 30, and 40% of cotton-seed cake residue (reinforcement) replacing the polyethylene mass (matrix). The composites were characterized for their physical–mechanical and morphological properties. The inclusion of cotton residue promoted an increase in moisture, from 0.05 to 0.37%, in water absorption 24 h (0.05 to 1.2%) and in thickness swelling (0.8 to 2.1%). The composites density did not show significant variation with the increase in the waste content. Regarding the mechanical properties, there was a decrease of 28, 52, and 81% for the modulus of elasticity, tensile, and tenacity, respectively. The results were similar when compared to other residual composites. In this way, it was possible to give a correct destination to the waste of low-density polyethylene and cotton-seed cake, producing a final material with high added value. [ABSTRACT FROM AUTHOR]

Study design:This is a case report.Objectives:Spinal cord atrophy presenting with late progressive myelopathy after many years of clinical stability is a rare and unexplained phenomenon after cervical spine surgery. The authors report and discuss the etiologies and outcomes of late postoperative myelomalacic myelopathy.Setting:This study was conducted in the Department of Neurosurgery, Centro Hospitalar S. João, Porto, Portugal.Methods:We report on two patients with insidious chronic progressive myelopathy that developed more than 10 years after complete removal of a cervical intramedullary ependymoma and after transoral odontoidectomy and occipitocervical fusion for craniocervical junction malformation. Differential diagnoses were formulated and review of the literature was performed.Results:In both patients, after several years of clinical stability, insidious onset of debilitating myelopathy and dependency ensued. The clinical history, serology, imaging and neurophysiological investigation excluded several putative etiologies: arachnoid adhesions, tumor recurrence, late vertebral instability, trauma, syringomyelia, radiotherapy, and demyelinating or infectious causes.Conclusion:Late neurological deterioration after cervical spine surgery is usually related to disease progression or surgery-related complications. Nevertheless, in some patients late myelopathy can ensue even in the absence of identified causes. [ABSTRACT FROM AUTHOR]