The paper reports on the determination of basic mechanical material parameters of several concrete and alkali activated concrete and fly ash mixtures intended for the construction of segmental lining used in TBM tunneling. The results of an extensive experimental program are discussed first. The principal attention is accorded to the experimental determination of specific fracture energy from a load-deflection curve, which, when compared to numerical simulations, shows certain inconsistency with the measurements of other material data. This is supported by teh derivation of the data from inverse analysis employing the elements of soft-computing. Dynamic simulation of crack propagation experiments is suggested to reconcile the essential differences and to identify the most important impacts affecting the results of experimental measurements. and Obsahuje seznam literatury
In this paper we describe the influence of NU7026, a specific inhibitor of DNA -dependent protein kinase, phosphoinositide 3-kinase, and AT M-kinase on molecular and cellular mechanisms triggered by ionising irradiation in human T-lymphocyte leukaemic MOLT -4 cells. We studied the effect of this inhibitor (10 μM) combined with gammaradiation (1 Gy) leading to DNA damage response and induction of apoptosis. We used methods for apoptosis assessment (cell viability count and flow-cytometric analysis) and cell cycle analysis (DNA content measurement) and we detected expression and post-translational modifications (Western blotting) of proteins involved in DNA repair signalling pathways. Pre-treatment with NU7026 resulted into decreased activation of checkpoint kinase-2 (Thr68), p53 (Ser15 and Ser392), and histone H2A.X (Ser139) 2 hours after irradiation. Subsequently, combination of radiation and inhibitor led to decreased amount of cells in G2-phase arrest and into increased apoptosis after 72 hours. Our results indicate that in leukaemic cells the pre-incubation with inhibitor NU7026 followed by low doses of ionising radiation results in radio-sensitising of MOLT -4 cells via diminished DNA repair and delayed but pronounced apoptosis. This novel approach might offer new strategies in combined treatment of leukaemia diseases., Aleš Tichý, Eva Novotná, Kamila Ďurišová, Barbora Šalovská, Radka Sedlaříková, Jaroslav Pejchal, Lenka Zárybnická, Jiřina Vávrová, Zuzana Šinkorová, Martina Řezáčová, and Literatura 42