ABSTRACT
BACKGROUND: The objective of our study was to determine the serum concentrations of protein S100B and neuron specific enolase (NSE) as well as their ability and accuracy in the prediction of early neurological outcome after a traumatic brain injury. METHODS: A total of 130 polytraumatized patients with the associated traumatic brain injuries were included in this prospective cohort study. Serum protein S100B and NSE levels were measured at 6, 24, 48 and 72 hours after the injury. Early neurological outcome was scored by Glasgow Outcome Scale (GOS) on day 14 after the brain injury. RESULTS: The protein S100B concentrations were maximal at 6 hours after the injury, which was followed by an abrupt fall, and subsequently slower release in the following two days with continual and significantly increased values (p<0.0001) in patients with poor outcome. Secondary increase in protein S100B at 72 hours was recorded in patients with lethal outcome (GOS 1). Dynamics of NSE changes was characterized by a secondary increase in concentrations at 72 hours after the injury in patients with poor outcome. CONCLUSION: Both markers have good predictive ability for poor neurological outcome, although NSE provides better discriminative potential at 72 hours after the brain injury, while protein S100B has better discriminative potential for mortality prediction.
ABSTRACT
This paper analyses the effects of decalcification in concentrated 6M NH(4)NO(3) solution on mechanical and microstructural properties of alkali-activated slag (AAS). Portland-slag cement (CEM II/A-S 42.5 N) was used as a benchmark material. Decalcification process led to a decrease in strength, both in AAS and in CEM II, and this effect was more pronounced in CEM II. The decrease in strength was explicitly related to the decrease in Ca/Si atomic ratio of C-S-H gel. A very low ratio of Ca/Si ~0.3 in AAS was the consequence of coexistence of C-S-H(I) gel and silica gel. During decalcification of AAS almost complete leaching of sodium and tetrahedral aluminum from C-S-H(I) gel also took place. AAS showed significantly higher resistance to decalcification in relation to the benchmark CEM II due to the absence of portlandite, high level of polymerization of silicate chains, low level of aluminum for silicon substitution in the structure of C-S-H(I), and the formation of protective layer of polymerized silica gel during decalcification process. In stabilization/solidification processes alkali-activated slag represents a more promising solution than Portland-slag cement due to significantly higher resistance to decalcification.
