Disorders of the neuromuscular junction

Acquired myasthenic syndromes are mostly autoimmune diseases with antibodies directed to ion channels of the presynaptic (Lambert Eaten Myasthenic Syndrome) or postsynaptic (Myasthenia Gravis) membrane. Although both of these syndromes can be treated rather effectively there is still a need for finding more specific therapies with less side effects. Furthermore many questions about the pathogenesis remain and finding the corresponding answers might not only increase the knowledge of myasthenic syndromes but also develop insights in general mechanisms of autoimmunity. Some excellent animal models for Myasthenia Gravis exist based on autoimmune or pharmacological mechanisms. Clinical features and pathogeneity of clinical myasthenic syndromes and characteristics of experimental models are described here

Friction and wear response of pulsed electric current sintered TiB2-B4C ceramic composite

This paper presents the friction and wear behaviour of TiB2-40vol%B4C ceramic composite disc in rotating sliding contact against SiC-ball and examines how the tribological characteristics of this system are affected by the interaction of wear particles, loading conditions and sliding speed. The transition from mild to severe wear is analytically modelled based on Linear Elastic Fracture Mechanics theory (LEFM). This model takes into account the mechanical and newly defined effective thermal induced stresses in the contact. The latter considers the Péclet number corresponding to the experimental parameters. Based hereon wear maps are constructed that show the transition in wear mechanisms, further corroborated by extensive SEM observation of the wear tracks. © 2014 Elsevier B.V.status: publishe