To evaluate the preclinical efficacy and safety of human mesenchymal stem cells (hMSC) rapidly expanded in growth medium for clinical use with human se rum and recombinant growth factors, we conducted a controlled, randomized trial of plasma clots with hMSC vs. plasma clots only in critical segmental femoral defects in rnu/rnu immunodeficient rats. X-ray, microCT and histomorphometrical evaluation were pe rformed at 8 and 16 weeks. MSC were obtained from healthy volunteers and patients with lymphoid malignancy. Human MSC survived in the defect for the entire duration of the trial. MSC from healthy volunteers, in contrast to hMSC from cancer patients, significantly improved bone healing at 8, but not 16 weeks. However, at 16 weeks, hMSC significantly improved vasculogenesis in residual defect. We conclude that hMSC from healthy donors significantly contributed to the healing of bone defects at 8 weeks and to the vascularisation of residual connective tissue for up to 16 weeks. We found the administration of hMSC to be safe, as no adverse reaction to human cells at the site of implantation and no evidence of migration of hMSC to distant organs was detected., R. Pytlík, C. Rentsch, T. Soukup, L. Novotný, B. Rentsch, V. Kanderová, H. Rychtrmocová, M. Kalmárová, D. Stehlík, M. Trněný, O. Slanař., and Obsahuje bibliografii
Transportation system safety and reliability pertain to the dominant factors affecting present life of human society. In this paper, we describe the method for an analysis and further subsequent optimization of complex transportation system safety and reliability based on their complex sensitivity investigation. Reasonable applications of this theoretical tool can also be used for improvement of complex transportation system resistance against terrorist activities.
This paper deals with a new approach to designing the micro-electronic system suitable for mass-parallel and neuronal structures realizations in which the high demand on safety and reliability is given. The presented concept is based on the FPGA platform. Authors point out various kinds of faults which can possibly occur during system cycle. Furthermore, authors introduce the Safety Core principle and define systems for which it is applicable. There are possibilities of using partial dynamic reconfiguration shown in this paper in the context of FPGA fabric testing, faults catching and correcting.
The effects of sleepiness, sleep loss and fatigue have been the focus of literally hundreds of studies dating back to 1896. Sleep disorders, like any other medical condition potentially affecting the safe performance of essential job functions or the safety of co-workers or the general public, require an individual assessment of the employee diagnosed with the condition to determine medical fitness for service and the necessity of any appropriate reasonable accommodations. The medical fitness assessment is a tool for maximum possible operational safety and the health and safety of all personnel in the railway industry. The article describes relevant international medical fitness standards for railway staff with special rules recommended for mental disorders, disorders of the central nervous system and use of alcohol, drugs, and other psychotropic substances.