In situ disordering of monoclinic titanium monoxide Ti5O5 studied by transmission electron microscope TEM.

The superlattice and domain structures exhibited by ordered titanium monoxide Ti5O5 are disrupted by low energy electron beam irradiation. The effect is attributed to the disordering of the oxygen and titanium sublattices. This disordering is caused by the displacement of both oxygen and titanium atoms by the incident electrons and results in a phase transformation of the monoclinic phase Ti5O5 into cubic B1 titanium monoxide. In order to determine the energies required for the displacement of titanium or oxygen atoms, i.e. threshold displacement energies, a systematic study of the disappearance of superstructure reflections with increasing electron energy and electron bombardment dose has been performed in situ in a transmission electron microscope (TEM). An incident electron energy threshold between 120 and 140 keV has been observed. This threshold can be ascribed to the displacements of titanium atoms with 4 as well as with 5 oxygen atoms as nearest neighbors. The displacement threshold energy of titanium atoms in Ti5O5 corresponding with the observed incident electron threshold energy lies between 6.0 and 7.5 eV. This surprisingly low value can be explained by the presence of either one or two vacant oxygen lattice sites in the nearest neighbors of all titanium atoms.

[CYP2C19 gene polymorphism in patients with myocardial infarction who use clopidogrel].

One of the foundations of the modern treatment of myocardial infarction (MI) is a combination antiplatelet therapy consisting of acetylsalicylic acid (ASA) and clopidogrel. Pharmacodynamic and clinical studies have demonstrated that the polymorphism CYP2C19 (CYP2C19*2 allele) is associated with a reduced antiplatelet effect of clopidogrel and an increase in the incidence of severe cardiovascular complications. The study included 97 patients with MI. Coronary angiography was performed with subsequent standard treatment of MI, including stenting of the infarct-related coronary artery. CYP2C19 polymorphism was determined by polymerase chain reaction. At 6months, outcomes were determined. The frequency of allele CYP2C19*2 was 22.7%. We found statistically insignificant differences in the prevalence of CYP2C19 gene polymorphism in different forms of myocardial infarction. In contrast to the authors, who previously published data on the effect of CYP2C19 gene polymorphism on cardiovascular complications, we found no differences according to genotype. CYP2C19 gene polymorphism does not influence the prognosis for the next six months, if to patient follow medical recommendations, including the regular use of clopidogrel.