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Myasthenia gravis (MG) is an autoimmune disease mediated by anti-acetylcholine receptor (AChR) antibodies and dependent on CD4 positive T lymphocytes (CD4+T) cells. MicroRNA (miRNA) is an endogenous small single-stranded non-coding RNA that involved in post-transcriptional regulation and plays an important role in differentiation and function of CD4+T cells. Increasing evidences have shown that changes of miRNAs happened in MG patients, which may participate in the occurrence and development of MG by regulating CD4+T cells, and miRNA may be a potential therapeutic target for MG. In this paper, relationship between miRNA and MG was reviewed in order to provide new ideas for further research on the pathogenesis and clinical diagnosis and treatment of MG. [ABSTRACT FROM AUTHOR]

[Objectives] The petaling of a ductile metal plate penetrated by a sharp-nosed missiles is a common damage mode. In order to analyze its formation process, numerical simulation is carried out. [Methods] First, a simulation model of striking the metal plate by sharp-nosed missile is established on the basis of experiments involving missiles perforating targets, and the material constants are acquired from material mechanical characteristic experiments. The petaling procedure is then studied, as well as the stress states of typical elements in the petaling cracking area. The influence on the simulation results is subsequently contrasted by different failure criteria. [Results] The results show that the petaling process is complex and can be mainly divided into four distinct stages:butterfly heaving, hole enlargement, petal appearance and expansion, and entire movement of damaged region. The stress states of the cracking area are complicated and the petaling shape cannot be sufficiently predicted by the constant strain criterion; this requires the introduction of the JC failure model which considers the influence of stress triaxiality. [Conclusions] The results of this paper can provide references for the modification of typical petaling cracking theory and evaluation.

In order to accurately fit the failure criteria in JC failure model, BW failure model, and MMC failure model, numerical simulations for metal materials Q345B and 921A under various loading conditions of compression, torsion, tension were performed in this work. The variation of stresses, indicated by stress triaxiality and Lode parameter, was investigated during the fracture progress. The results indicated: (1) exclusive of torsional loading, the stress distribution varied in the cracking plane as the crack growth; (2) the average stress triaxiality and Lode parameter are more suitable for describing the stress status; (3) for specimens having the same size, the value of average stress triaxiality was dependent on metal properties. This work would provide useful knowledge for obtaining the failure criterion from material failure experiments. [ABSTRACT FROM AUTHOR]