A look inside epitaxial cobalt-on-fluorite nanoparticles with three-dimensional reciprocal space mapping using GIXD, RHEED and GISAXS.

In this work epitaxial growth of cobalt on CaF2(111), (110) and (001) surfaces has been extensively studied. It has been shown by atomic force microscopy that at selected growth conditions stand-alone faceted Co nanoparticles are formed on a fluorite surface. Grazing-incidence X-ray diffraction (GIXD) and reflection high-energy electron diffraction (RHEED) studies have revealed that the particles crystallize in the face-centered cubic lattice structure otherwise non-achievable in bulk cobalt under normal conditions. The particles were found to inherit lattice orientation from the underlying CaF2 layer. Three-dimensional reciprocal space mapping carried out using X-ray and electron diffraction has revealed that there exist long bright 〈111〉 streaks passing through the cobalt Bragg reflections. These streaks are attributed to stacking faults formed in the crystal lattice of larger islands upon coalescence of independently nucleated smaller islands. Distinguished from the stacking fault streaks, crystal truncation rods perpendicular to the {111} and {001} particle facets have been observed. Finally, grazing-incidence small-angle X-ray scattering (GISAXS) has been applied to decouple the shape-related scattering from that induced by the crystal lattice defects. Particle faceting has been verified by modeling the GISAXS patterns. The work demonstrates the importance of three-dimensional reciprocal space mapping in the study of epitaxial nanoparticles.

[The use of phenobarbital and carbamazepine (finlepsin) in children with epilepsy and cerebral spastic palsy with epileptic syndrome]. / Osobennosti primeneniia fenobarbitala i karbamazepina (finlepsina) u detei bol'nykh épilepsiei i tserebral'nymi spasticheskimi paralichami s épilepticheskim sindromom.

Based on examining 20 patients with infantile cerebral paralyses (ICP) and 18 epileptic patients aged 6 to 14 years it has been demonstrated that the effective doses of carbamazepine do not differ (14-27 mg/kg/day) in both the groups, whereas the effective doses of phenobarbital are higher (5.3 mg/kg/day) in ICP patients than in those suffering from epilepsy (3.65 mg/kg/day; P less than 0.05). In this case the blood concentration of both carbamazepine and phenobarbital was lower in ICP patients (5.1 and 23.1 mg/l, respectively, than in epileptic patients (8.2 and 28.8 mg/l). The drug levels in the blood serum were measured by high-effective liquid chromatography. It was assumed that the efficacy of the lower drug concentrations in ICP patients was related to greater permeability of the blood-brain barrier or with higher sensitivity of "epileptized" neurons in them as compared to epileptic patients. The comparison of the doses and blood concentrations may point to more intense biotransformation of the antiepileptic agents in the body of ICP patients than in patients suffering from epilepsy.

[Serotonin and ATP metabolism in the thrombocytes of patients with different stages of cerebrovascular disorders of the ischemic type]. / Osobennosti obmena serotonina i ATF v trombotsitakh u bol'nykh s raznymi stadiiami narusheniia mozgovogo krovoobrashcheniia ishemicheskogo kharaktera.

The patients with ischemic lesions of brain circulation showed marked biochemic changes of blood platelets. Obviously it plays an important role in the development of the given pathology. In the acute stage of the stroke there was a decrease of serotonin and ATP content in platelet which gradually increased along with the development of the disease. In the period of the residual phenomena the level of the studied indices appeared significantly increased in comparison with the normal one. In the patients with transferred lesions of the brain circulation at the acute stage serotonin and ATP content was not below the normal level. Later on the increase of these parameters took place and in the period of the residual phenomena theirlevel in platelet did not differ from serotonin and ATP content in blood platelets of the patients with the ischemic stroke.

[Oxygen transport function of hemoglobin in several neurologic diseases]. / Kislorodotransportnaia funktsiia gemoglobina pri nekotorykh nevrologicheskikh zabolevaniiakh.

Data on the oxygen transport function of hemoglobin in patients with craniocerebral injury, cerebrovascular disorders, and epilepsy are presented. The role of 2,3-diphosphoglycerate contained in the erythrocytes, and of changes of the hemoglobin affinity to oxygen in the oxygenation of tissues in such patients is discussed. It is concluded that determinations of 2,3-diphosphoglycerate content in the erythrocytes be applied in clinical practice for diagnosing a number of nervous diseases accompanied by symptoms of cerebral hypoxia, so that the latter could be compensated in due time.